Digital Surfacing

Digital (or Direct) Surfacing

Created by: Tony LeBlanc
Last Updated: 11 January 2013
Last Updated by Tony LeBlanc

Overview

Digital (also called Direct) Surfacing refers to the manufacturing process by which a multifocal (progressive) design is ground onto the back surface of a standard semi-finished SV lens blank.  This eliminates the need for the lab to stock lens blanks in different combinations of base curves and add powers for a traditional progressive design, and also allows each prescription to be optimized for the patient.
Processing digital surface designs in a lab involves the use of a Digital Surfacing (or Lens Design System, herein called the LDS) calculation program, provided by the Digital Surfacing design provider (lens vendor), and equipment specially designed to cut these surfaces into a lens, both of which must interface with the lab management software (LMS) used by the lab. 
The LDS replaces the traditional surfacing calculations done by the LMS, and also provides additional information needed for DS jobs. Communication between the LMS and the LDS is done by means of communication packets, either in the form of .LDS and .LMS files (as described in the VCA DCS 3.08) or as communication packets through a web service which contain the same data as the .LDS and .LMS files.
In one model, the digital surfacing calculation software (the LDS from the lens vendor) runs on a PC on the lab's network, accepts files in VCA format from the LMS describing the job to be processed, and returns both a result file, for use by the LMS, as well as a surface map file (SDF) for use by the DS manufacturing equipment.  The DS manufacturing equipment typically includes a generator, a polisher, and a laser engraver, all of which are connected to the LMS via a serial connection, and to the network using a network connection (to retrieve the map files).
In a typical (traditional) job, the flow of information looks similar to the following:

In the case of a DS job, there are both more pieces involved and more transmission of data, as follows:

As a result of the additional interfaces, there are additional steps required to configure OMICS to process digital surfacing jobs:
 Specify calculation interface(s)
Set up digital surfacing lens styles
Set up base curve selection for digital surfacing lens styles
Configure VCA Label Tables if necessary for interface-specific requirements
Configure device interface for digital surfacing equipment
Configure device interfaces for DS equipment


1.1 Use of LDI (initialization files) with Digital Vendors
Because digital calculators are updated with new designs and features, OMICS recommends using LDI files to determine which labels are sent to a particular interface. This facilitates easily adding new VCA labels, as required, to existing interfaces.
On the "Digital Surface Types" screen is a field entitled "Full path of INIT (LDI) file. This should be set to the full pathname where the LDI file either exists, or where you wish it to exist.
The LDI file can be created and edited from the DS type screen, using the button "View/Edit LDI file":

As long as the "Full path of INIT (LDI) file" is set, the button is enabled.
Upon clicking the button, OMICS attempts to open the LDI file. If it does not exist, you will be prompted:

If you answer "yes", OMICS will create an LDI file with the appropriate default labels according to the vendor selected on the screen (based on labels used for each vendor as of January 2011). The normal edit screen (described next) will then appear.
If the file already exists, the file is loaded and the editing screen displayed:

This is a standard Windows edit window, changes can be made to the file, as required. It is important to follow the format presented – inclusion of comment lines or invalidly formatted lines may adversely affect the operation of the interface.
Editing is done with standard Windows editing keys – note that to do a line feed (create a new line), you'll need to use <ctrl><enter> instead of just <enter>.
When you click "save", the file is saved – if OMICS cannot write the file (usually this is a permissions problem), you'll get an error similar to this:


1.2 Vendor Specific Communications Requirements
Some lens vendors handle some of the fields in the standard VCA interface differently; to handle these differences, OMICS allows for the creation of digital "device" interface records.  The workstation "DS" is reserved for "Digital Surface" interfaces; the port number of the interface corresponds to the "Digital Surface #" used in this file.
To illustrate, take the above example, for digital surface type 03.  If this is a Shamir lens interface, we need to create a device interface record for Shamir.  This would be done by creating an interface record for workstation "DS", and port "3" (corresponding to digital type "03", as follows:

The selection of "SHAMIR" in the Special Device Modifier indicates that Shamir-specific interpretations of VCA labels should be used when sending requests to the Shamir calculation engine. 
If the digital design supports blocking prism (either in lieu of or in addition to embedded prism in the design), set up the "Blocker maximum prism", on the Blocker tab, to a non-zero number to indicate blocking prism is supported (see separate section on prism).
For Epson-Seiko calculations, the interface normally allows the Epson-Seiko calculations to select a block size and override those selected by OMICS.  However, in some cases the lab may NOT wish to use the block sizes selected by Epson-Seiko - this can be accommodated by unchecking the "Save new block info when received from device" checkbox.
Note that for "DS" records, the serial communication parameters (baud rate, data bits, stop bits, parity, flow control) have no effect.
For Shamir, Opto-Tech and IOT digital calculations, the block is selected by OMICS and sent to the DS calculator. If the selected block will not work for a particular Rx, the lab will need to manually select a different block for the job, and resubmit the job to the DS calculator. For Essilor, Epson-Seiko and Indo calculations, the block is selected by the digital calculator and sent back to OMICS, so the "Save new block info when received from device" option should be checked.
1.3 Prism on Digital Designs
How blocked and embedded prism is handled on a job depends upon the particular DS calculator. Prism can either be incorporated in the design that is ground onto the back surface of the lens, or it can be blocked on a prism blocker, or it can be a combination of the two. Note that, unlike a non-digital job, prism cannot be sent to the generator to be ground as part of the generating process, as what is cut onto the back surface of the blank is the progressive design.
The "Blocker Maximum Prism" field deserves explanation as it is used for the DS interface. This parameter does not specify a limit for prism to be included in a design (this is determined by the DS processor itself), rather, it operates as a Y/N switch to specify whether the lab supports blocking prism or not. If set to 0.0, then parameter PBOK=0 is sent to the DS engine, indicating that the lab will block a maximum of 0 dioptres of prism; any non-zero value will send PBOK=1, indicating that the lab can block some (or all) prism. The amount of prism to be blocked will be sent back to OMICS in the LMS file in the KPRVM parameter. (Shamir, IOT, Opto-Tech and Essilor all support this method of blocking prism in addition to prism incorporated into the design).
In the case of Epson-Seiko, they support either blocking prism or incorporating it into the design, but not both at the same time. This is controlled by a setting in the Epson-Seiko DS calculator itself. This cannot be selected on a per-job basis, and the Epson-Seiko calculator ignores the PBOK label if sent in the .LDS file, which would normally be used by the LMS to indicate whether or not blocking prism is to be used.
In addition, Epson-Seiko does not use the standard VCA labels to identify blocked prism, so the device setup screen must be set in OMICS to agree with how the Epson-Seiko calculator is set up. In the device setup for Epson-Seiko, if blocked prism is to be used, the LDPRV? = KPRV? field must be checked.

Indo always blocks prism and sends it back in the KPRV* fields, so the setting of the prism fields in OMICS has no effect for Indo.2.0 Create Digital Surfacing Lens Style(s)
Once the interfaces to the digital surfacing calculation programs have been set up, a lens style must be set up for each different digital surfacing design to be used.  The designs are purchased from the lens vendor(s), and the lens vendor will provide a "design name" for each specific digital surfacing design that the lab is authorized to manufacturer.
Lens styles for digital surfacing are set up exactly as they would be for any new lens style. For example, to set up a new digital surfacing style "01013", using the calculation engine specified previously as digital surfacing interface "01", a screen similar to the following would be set up:

Some fields to note for this type of lens, on the General tab::
Minimum SegHt and Min SegHt Action - specifies the lowest seg height that can be used for this lens design. Setting this, and setting the Action to "E", prevents the user from requesting a seg height that is invalid for the digital design.
Maximum Add - specifies the highest add power that can be manually entered for this lens style.  This prevents requesting invalid add powers from the digital surfacing calculation engine, which can cause errors with some engines.
Digital Type – this identifies which digital surfacing interface to use for this lens style, if set, it activates the fields on the Digital tab. This number corresponds to the digital type number discussed in section 1.0.

Some fields to note for this type of lens, on the Devices tab::
VCA LNAM – this is what will be sent to the digital surfacing calculation engine, and specifies which calculation design to use. This will be specified by the digital calculation provider, and must match exactly. (Note that VCA Label Tables can be used instead of setting the LNAM by OMICS lens style – for Essilor, it is necessary to use the VCA Label Tables as the LNAM value is based on the material and color of the lens, as well as the lens style).
Subs Add For Cyl – For DS designs which do not use BRS requests to determine the best base curve to use, there are two options.
If this option is checked, this causes OMICS to substitute add power for cylinder power in the base curve selection charts. This option changes the meaning of the top line of the base curve chart to be add instead of cylinder (for example, Shamir uses this method of base curve selection for their freeform designs). In this scenario, cylinder power has no effect on base curve selection.
If this option is UNchecked, OMICS will use a standard base curve chart, with cylinder across the top, and sphere down the side, but will add the add power to the sphere power if the sphere power is plus (greater than 0). Thus, an Rx of +2.00 sphere, -1.00 cylinder, with a 2.00 add, would use the entry in the chart for a +4.00 sphere, -1.00 cylinder.
For an Rx of -2.00 sphere, -1.00 cylinder with a +2.00 add, OMICS will use the chart entry for -2.00 sphere, -1.00 cylinder (the add is not considered because the sphere power is minus). If "Use BRS to get BC from DS" flag is used to get the base curve selection from the DS engine, then the "Subs Add for Cyl" flag has no effect.
Center Design – if this design is automatically centered to frame center on the blank (as with Shamir designs), or if you wish the design to be centered for frame center on the blank (as with IOT designs), check this box. When checked, this causes OMICS to assume the design is centered on the frame center when calculating minimum blanksize, and will cause the IOT VCA label "_DECM" to be set to 1, indicating that the design should be centered for the FGC. Note that Epson-Seiko does not support centered designs (as of this writing). This optimizes the blank, and results in the smallest possible blanks being used for jobs.
Near Vision Digital – if the design is a near vision digital (lens is to be verified only at the near and not at distance), check this box. This causes OMICS to print near power (compensated or not) for validation on the work ticket.
Use BRS to get BC from DS – the VCA 3.07 standard provides a way for an LMS to request the base curve range to use for an Rx, rather than using a base curve chart. Checking this box will cause OMICS to request the base curve range for the Rx using a BRS request, created as an LDS file in the outgoing LDS folder. OMICS will then look for a .BAS file response, and select a lens that falls within the base curve range specified.
LDS selects blanks to use – if the digital calculator will dictate the blanks to use (by OPC), check this box. If checked, OMICS will not attempt to do blank selection at all, and will expect the LMS file that is returned from the digital vendor to include the OPC code(s) of the donor blank(s) to be used for the job.
Trace required – if the digital vendor requires a trace to be present for this design, check this box. OMICS will not allow creation of a job using this design without a trace present. Remote orders using this design which do not have a trace will be saved Unvalidated.
_TKADOC VALUE – this field (used by the IOT calculator), can be specified for specific designs. The valid values are (these descriptions come from the IOT documentation):
_TKADOC=0. No adjustment is made; the lens will be calculated to respect the minimum center thickness and minimum edge thickness on the frame shape. No control is made of the thickness outside the frame. This optimizes positive lenses with frame shape to the maximum. This option can produce negative thickness in the cribbing region, which means that the cutting tool will remove all material and can even be cutting into the alloy. Consult your free-form machine provider on the risks of this option for the cutting tools and polishing pads.
_TKADOC=1. The surface is considered to be optically valid on the whole cribbing ellipse, and therefore curvatures are continuous on the whole cribbing region. Thickness for positive lenses cannot be optimized to the frame as much as would be desirable because the elliptical cribbing region is restricting the minimum thickness.
_TKADOC=2. Thickness is calculated so it will respect the minimum center thickness and minimum edge thickness on the frame. The surface is propagated outside the frame increasing curvature within the allowed ranges of the free-form machinery, while avoiding that the concave surface cuts the convex surface. Thickness for positive lenses with frame shape is optimized as much as is possible without negative thickness and within the range of the free-form limitations. Improvement of thickness with this option respect to _TKADOC=1 can be between 0.4 and 1.2mm, depending on prescription and frame shape.
Min Thick at Crib Diam – this corresponds to the MINTHKCD field defined in the VCA specification – edge thickness on a plus lens is normally optimized to give the thinnest possible edge, and thus the thinnest possible center, for the best cosmetic result. Unfortunately, in the case of cut-to-polish equipment, a moderately strong plus lens in a small frame can result in an edge thickness at the crib diameter which is very thin. On the generator, this can result in cutter crash (where the blade will cut into the alloy), and on the polisher, this can result in the sharp edge of the cribbed lens cutting into the soft polish block. A lab can get around this problem by specifying a minimum thickness at the cribbing diameter – thus, if the lens is so thin/small that it might cut into the polish tool, this parameter would increase the thickness by requiring the edge at the crib diameter to be 0.5mm (for example). Please note that this will (obviously) increase the overall thickness of the finished lens as well (the finished ET could be greater than is cosmetically optimal).
LML basename – this field indicates what engraving template base files should be used for this design. This field is used if OMICS is creating the .JOB files for the LaserOp engraver (using the LensMarkJobBuilder program), and is used as the base name for the ENGMASK for a laser connected with VCA protocol. (See the separate section on interfacing laser engravers).
Style-specific VCA labels and values can be set up on the "Optional" tab for the lens style. For example, to always force CORRLEN=14 for a particular style, add the CORRLEN label, with a value of 14, to the label grid as follows:

Note that the CORRLEN must be configured as one of the labels to be sent to the calculator, in the LDI file for that calculator (see section 1.1 which discusses LDI files). Generally, setting labels in this section will be done during discussions with your OMICS rep and the digital vendor, during set up of a new design.
For Indo designs, since they use encrypted surface point files for some equipment, three labels should normally be set up for each Indo lens design:

LDCRYPT and LDTYPE will be sent to equipment which requests it, indicating the surface data is in Indo encrypted format. The _OPTIM=1 label instructs Indo to optimize thickness for the design.
3.0 Blank Selection for Digital Surfacing
Since a back-surface digital surface job has the power of the lens, including the corridor, ground onto the back surface of the lens, the lens selected from inventory is a SV-style lens.  (Other digital offerings retain the progressive design on the front, and calculate an atoric curve for the back to minimize distortion).
The remaining blank selection discussion does NOT apply to Essilor or Vision Ease calculations, as these vendors determine the blanks to use. Note that it is the lab's responsibility to ensure they have the proper lenses set up in the OMICS inventory system for use with Essilor or Vision Ease calculations.
When using blanks that are pre-marked, they should be treated similar to a polarized lens, and NOT cribbed, to avoid removing the reference marks needed for finish blocking. These reference marks are used to ensure proper location of the horizontal (again, similar to polarized lenses). Whatever lenses are used for digital surfacing jobs, an alias needs to be set up to tell OMICS which lenses to use for the digital surface lens style.  For example, to use a regular, semi-finished lens blank when lens style 01013 is entered for a job, an alias item similar to the following should be set up:

Some digital surface vendors provide special SV-style blanks for this purpose, which have markings already embedded into the lens to facilitate finish blocking.  Those blanks from Epson-Seiko, for example, are loaded into the OMICS inventory system with all technical information, including OPC codes, using the lens style FFSF (digital surface semi- finished), to differentiate them from regular SV lenses.  Other vendors provide SV blanks which are used only for digital – Essilor lenses can be found using code SVD (for SV Digital), while Zeiss pucks use the lens style PUCK.
The base curve selected for a digital job is different than that selected for a traditional progressive design; this is because the add power is ground on the back of the lens instead of on the front.  The suggested base curve charts from lens vendors for digital jobs are based on add power in addition to sphere and/or cylinder powers.  When OMICS determines optimal base curve for a digital job, it takes the add power into account when looking up the chart.  When entering a base curve chart for a digital design, the add power should be added to the sphere power (in the chart), and the curves entered using the combined sphere + add for the sphere column (in the case of Epson-Seiko charts), or the add power should be substituted for the cylinder power (as in the case of Shamir base curve charts).
Note that the chart number used for a digital job is determined by the chart number of the digital lens style, NOT the chart number of the SV lens actually selected.
It is possible to set the alias up so that OMICS can select the best design to use based on the seg height of the job. For example, take a digital design available in 3 corridor lengths, with different minimum seg heights, as follows:
DesignMin Seg Height
DIG1818
DIG1414
DIG1111
The lens style setup for each lens must have the minimum seg height set, and the "Min SegHt Action" option must be set to "Y":

Then set up the alias file to start at style DIG11, aliasing to DIG14, DIG14 aliasing to DIG18, and DIG18 aliasing to SV.

When entering an order, always enter with lens style DIG11 – OMICS will then check the seg height, automatically switching the design to DIG14 or DIG18 if necessary, and will select the SV lens from inventory to process the job.
If the digital design is one for which the DS calculator can provide the allowable/preferred base curve range, OMICS can use that method instead of using charts to select the base curve. This is set up on the lens style in OMICS, using the checkbox called "Use BRS to get BC from DS":

When this lens style is used, OMICS will request the base curve to use from the DS calculator by creating a BRS file in the outgoing folder, and will display a message "REQUESTING BASE CURVE FROM DIGITAL PROCESSOR" during blank selection while it does this. If it does not receive a response back from the processor, or no blanks are available with the base curve selected, the appropriate message will be given.

3.1 "Reverse" Blank Selection
OMICS supports selecting the largest blank first for digital designs. This approach can be used with the Shamir Prescriptor, where OMICS will pick the largest blank that could be used; the Prescriptor will send back the smallest diameter and thinnest blank thickness that could be used, and OMICS will re-select the blank, if possible, based on these criteria, when processing the LMS file.
Normal blank selection rules would select the smallest blank first, and submit it to the Prescriptor. Then, if the job could not be run on that blank (either because of size or thickness), the Prescriptor would send back an error, the lab would manually select a different blank on the order, and resubmit the job. This process would continue until the job was calculated successfully by the Prescriptor, or the lab had no other blanks to use.
To avoid the need to reselect blanks and resubmit jobs to the Prescriptor because of blank size or blank thickness, Shamir sends back a minimum diameter and minimum blank thickness in the information packet sent back to OMICS. In this scenario, OMICS will pick the largest blank first, the Prescriptor will send back a minimum diameter (MINDIA) and a minimum blank center thickness (MINBCTHK) in the LMS file. OMICS will then check the inventory to see if a blank exists that is smaller than that originally selected, with the exact same front and back curves, and which respects the MINDIA and MINBCTHK – if such a blank exists, it will be used, with appropriate inventory adjustments made to the origjnal blanks.
An example might help to illustrate how this would work. Take 3 lenses available from manufacturer SHAM, all the same base curve, with exactly the same front and back curves:

All 3 blanks have a true curve of 6.341; the blank thicknesses are 7.6 (70mm); 10.6 (76mm), and 13.6 (85mm).
When a job is created in OMICS which uses this SHAM blank, OMICS will select the largest blank (the 85mm blank) first, and send that information over to the Prescriptor. In the LMS file returned to OMICS, the Prescriptor includes the lines MINDIA=74 and MINBCTHK=7.0.
OMICS will then check the lens blank inventory, looking for blanks from the same vendor that are smaller and/or thinner, which could work instead of the 85mm selected.
When checking the 70mm blank, the lens is smaller than MINDIA, so it is rejected. OMICS next checks the 76mm blank, finding that it has the same front and back curves as the 85mm blank originally selected (and used for the Prescriptor calculations), and also respects the MINDIA and MINBCTHK sent back from the Prescriptor. OMICS will thus substitute the 76mm blanks in this job, making the appropriate inventory adjustments to reverse the 85mm blanks. Since the front and back curves are the same, the calculations done by the Prescriptor to produce the SDF and LMS files are still valid. The lab thus avoids selecting the 70mm blank first, and having to manually select the 76mm blank after the Prescriptor rejects the first submission, and resubmit, improving the turnaround time for the job and reducing manually modifications of the order.
Use of this "reverse" blank selection logic can be triggered for specific combinations of lens style and material – when selection from one style to another is used (for selection of corridor length based on seg height), the presence of "reverse" selection at any step will cause reverse selection to be used for the job.
To trigger reverse selection in OMICS, a flag exists on the alias setup:

4.0 Setting Up Devices
There are 4 types of devices that are used in the production of digital surface lenses:
Surface Blockers - When information is sent to a surface blocker for a digital surface job, the cylinder axis will always be sent as 0.  This is because a standard SV lens blank is used, and because everything is ground onto the back surface of the lens, there is no need to align the cylinder axis with anything on the front (in a traditional progressive, the front of the lens must be aligned and then the cylinder axis marked relative to that). Data for a digital progressive to be manufactured on a SV blank can be sent to the blocker either as a progressive lens, or as a SV lens. The default it to send it as a progressive – to tell OMICS to send the lens as a SV lens to the blocker, check the following box:

Generator - to cut a digital surface design, a compatible generator must be used.  Most of the differences in the interface are handled automatically by OMICS, based on the job itself being a freeform job (ie. using a lens style which has a freeform type associated with it).  However, since a digital surfacing generator is also a true cut-to-polish, that fact needs to be identified in the device configuration screen, by checking the "Cut to polish" flag::

Note that, since the topography files produced by the digital surfacing calculations are stored on the LMS network, the generator must also be connected to this network so that it can locate the files.
Polisher - since a true cut-to-polish generator is used, traditional fining is not done on lenses produced on this generator.  However, the information sent to the polisher varies from a traditional job.  An entry for the interface to the polisher must be set up similar to the following:

The setting of the "Special Device Modifier" to "IFLX" indicates to OMICS to send different information to the polisher for some fields (for example, cylinder axis).
Laser Engraver – see section 6.0 for a discussion of the options for interfacing a laser engraver.
5.0 Digital Surfacing Processor
The Digital Surfacing Processor runs similar to the Job Tracker or Remote Processors in OMICS, as a basically unattended process which sends and receives information from the various digital surfacing calculation engines.

The number of seconds that the DSP pauses between each loop of checking all "in" folders defaults to 5 seconds, but can be changed on the screen.  A log file is maintained on the DS device setup record (as with other devices), which shows the communication that takes place between OMICS and the digital calculator in question.
Firstly, the DSP monitors the OMFREEPR file, which contains orders that need to be sent to the different calculations engines.  For each order listed, the DSP gets the digital type for that lens style, and checks for a "DS" device record for that type.  It creates a flat file, in VCA format, in the "out" location specified for that digital type, using any special processing associated with the "DS" record.
Secondly, the DSP monitors all "in" folders for all digital types.  When a file with an "LMS" extension is found (in any of those folders), it is processed by the DSP, which involves saving the information from the incoming file in the device record for the correct job, including the LDPATH of the design file (the back surface topography file to be generated). Usually, the results from the calculation engine also require recalculation of the SET and ACTUAL value on the job.  When viewing the device data on a job, it's easy to tell if the data has been updated by the DSP by whether or not the LDPATH setting, at the top of the screen, has been set, as in the following example:

For digital jobs, there is a button called "View Digital Files" which will be active (it is not active for non-digital jobs). Clicking this button will show the contents of the BRS, BAS, LDS and LMS files for this job (these files are taken from the ARCHIVE subfolders, therefore the ARCHIVE subfolders must exist under the incoming and outgoing folders for the various DS interfaces).

In addition to the "View Digital Files", the lab can also "View PROC records", which show device-specific data sent from the digital calculator. This data shows VCA data which OMICS doesn't use – any such labels are stored, with their values, and will be "passed-through" to any devices which request it. Also shown (as in the example below), are the device-specific values, where different values can be stored for a label, and sent to the appropriate device when requested. In the example below, LDPATH has different values for different models of generator:

The lab can set up an icon to automatically start the DS processor by using "ff" as the auto command for the workstation (usually we use "DS" as the workstation number, but that is not mandatory). Whatever station number is used, the workstation setup screen can be set up with "ff" as the auto command.
6.0 LaserOp Engraver
A laser engraver is needed to mark (engrave) the blank with reference marks which are then used to mark the lens visibly so the reference points can be easily located, for both power checks and edging purposes. Often, a symbol is also engraved indicating the design of the lens, the add power and index can be engraved – the lens could even include the name of the patient if desired.
To engrave anything on a lens, a template is first required, which describes the symbols and options to be engraved, and their location on the lens. In the case of the LaserOp engraver, these templates can be created using a utility called "cMark", which is provided by LaserOp. The resulting template files are stored as files with the extension .LML; depending on the interface method, they may be stored locally on the engraver computer, on a shared folder on the network, or on the Shamir Prescriptor server. There is usually a different template (.LML) file for each different digital design, and a separate file for each eye (since the engravings will be reversed between the left and right eyes). For the LaserOp engraver, the template file is specified in the "LML basename" field on the Digital tab of each lens style.
An engraving is an etching of a design into the surface of the lens. The clarity of the etching is greatly affected by the material of the lens, any tints on the lens (imbibed or applied), and any treatments on the lens (again, whether imbibed or applied).  The engraver allows many different "Material Parameter Sets" to be set up to allow for different depths and widths of etchings (as well as other parameters), for different combinations of materials and treatments.  LaserOp technicians can assist a lab in determining the optimal combinations of parameters on the engraver for the materials used.
The Parameter Marking Set is set on the material file if OMICS is creating the .JOB file using LensMarkJobBuilder; if the LaserOp is connected via a serial VCA connection, it is controlled by the LMATID value.
There are 3 options for how a laser engraver can be incorporated into the DS processing at a lab:

• using .JOB files created by the LDS calculator (LaserOp laser only)
• using .JOB files created by OMICS (LaserOp laser only)
• serial VCA interface

6.1 .JOB files create by LDS calculator
In this configuration, the Shamir Prescriptor looks after creating the .JOB files, placing them into a shared folder which the LaserOp engraver is configured to look in. Because the Prescriptor has no means of knowing when jobs are shipped, OMICS should be configured with the location of the .JOB files in the digital type setup. Note, the path for LMS and PRM files should be left blank in this case – only the path for the .JOB files should be set. OMICS is configured to check for a .JOB file when a DS job is shipped, if the .JOB path is set.
6.2 .JOB files created by OMICS
If OMICS is to create the .JOB files (when the LaserOp engraver is configured to check for .JOB files instead of being connected via VCA serial interface), the appropriate paths need to be set in the digital type setup, and the LaserOp programs need to be present in the OMICS60 folder (or wherever the default OMICS folder is located).
When interfacing the LaserOp Engraver in this way, ensure that all necessary fields are set up in OMICS.  This interface is unlike interfaces with other Optical machinery; parameters are set up in OMICS, and OMICS then creates files which the engraver retrieves in order to engrave a lens.  Rather than requesting information from OMICS (as other devices do), OMICS must prepare the files and leave the information on the network where the engraver can retrieve it at will.
There are 4 files shared between the engraver and OMICS - the LML or template file (describing what is to be engraved on the lens); a Parameter file specifying parameters to be replaced on a particular template for a particular job; the JOB file, created by OMICS and used by the engraver, and the back surface topography file, created by the digital calculation software.
For each digital surfacing type that will use the engraver, the location of the above fields must be set up in the Digital Surfacing Type file (described earlier in "Specify Calculation Interface").
If the LML path and PRM path are both set, this will trigger OMICS to create the .JOB file using LensMarkJobBuilder.
The Marking Parameter Set can be set in two places – first, the default is set on the material file, on the Devices tab. For example, if a Marking Parameter Set name called "CR39" exists on the engraver itself, then "CR39" would be entered in this field on the Devices tab to tell the engraver to use that Marking Parameter Set for that material.

Exceptions can be set up by combinations of material and treatment (for treatments already on a lens, such as photochromatic and polarized), and for material and applied treatment (such as ARC, tinting, etc.).
Under "System Parameters", then "Digital Surfacing", select "LaserOp Engraver MATID".  In this table, the lab should set up an entry for each combination of material and treatment/addon that should use a different material parameter set from the standard. 
For example, to use material parameter set "CRARC" for CR39 lenses (P) with an addon called "ARC", set up an entry similar to the one below. When a digital surface job has an addon or pretreatment called "ARC" and is material "P", OMICS will specify CRARC to be used instead of the default "CR39" material parameter set.


6.3 Serial VCA Interface
The third option is the connect the laser engraver to OMICS using a standard VCA serial connection. In this scenario, the engraver still needs to know what template and what Marking Parameter Set to use for a job.
With the LaserOp engraver, the template is sent in the ENGMASK label, and the basename comes from the "LML basename" on the lens style. OMICS will take the basename, and append "L" or "R" to the basename for each of the left and right eyes, respectively


How the engraver determines theowHH Marking Parameter Set is determined by "marking parameter set name" option under "VCA connection settings" (see left)
The default setting for "marking parameter set name" is {LMATID}{ACOAT}{TINT}. The dashes are important, so if a job had an LMATID of 12, with ACOAT and TINT both blank, the parameter set name would be "12--" (including the dashes).
Since ACOAT and TINT are used differently by different devices, and since OMICS can include coatings and colors when it determines LMATID, the preference is to set the "Marking parameter set name" to just {LMATID}.
In OMICS, the LMATID should be set using the VCA Label Table – care needs to be taken to ensure that all materials that will be engraved have the appropriate LMATID entry created for them.













7.0 Digital Parameters System Variable Screen

Prompt for recalc on modify – if checked, the user will be asked, at the end of modifying a digital job, whether or not to resubmit the job to the DS calculator. If a lab has an arrangement with the digital processor to compensate based on a method other than a per job or per lens basis, then there is no need to ask whether or not digital calculations should be re-done – this flag can be left un-checked, and every job will be resubmitted each time it is modified.
However, when a lab pays for digital jobs on a per-job or per-lens basis, the user can decide whether or not to resubmit the job for calculation. For example, if a job is modified to change pricing information or other information which has no effect on the lens, there is no need to recalculate it. However, if the job requires an Rx change, or a change to the frame measurements, then recalculation should be done. This flag puts the decision in the hands of the operator, based on the changes made:


Laser JOB files by order num – if checked, this causes the .JOB files that are created for the LaserOp laser engraver to be named based on the order number instead of the tray number. This has effect only if OMICS is creating the .JOB files – if the DS calculator creates them directly (as with Shamir), this checkbox has no effect.
Digital LDS/LMS etc files by order num – if checked, this causes the LDS and LMS files (and BRS/BAS files, if used) to be created using order number rather than tray number. While this removes any confusion resulting from re-use of tray numbers, it will result in a larger number of files in the ARCHIVE folders for the various files.
Digital Surface Device Name – this is the printer that work tickets will be printed to by the OMICS DS processor (when results are returned from the DS calculator). This is a duplicate of the same field also present on the Orders1 tab, and is included on this tab for convenience.
How long to wait for BAS file – when a lens style is set up to request the base curve from the DS calculator, OMICS creates a BRS request, and then must wait for the response in the form of a BAS response. Since we do not want to wait forever if the DS calculator is not running or otherwise does not return an answer, the lab can set the timeout (in seconds) to wait for the response. If a BAS response is not received by the end of the timeout period, an error message will be displayed and blanks will not be automatically selected.

Details of Digital Surfacing Interface
The information in this section is not required in order to run the digital surfacing interfaces, but is provided for those individuals who wish to know more about how the interface works behind the scenes. For purposes of this discussion, consider a DS calculator set up in C:\DS, with folders as follows:
C:\DS\LDS – where DS looks for LDS files to process
C:\DS\LMS – where DS places LMS (result) files for OMICS
C:\DS\SDF – where DS places the .SDF files used by the generator and polisher
An order is entered into OMICS, using a digital design. In order to pick the correct SV lens blank to use, OMICS needs to know what base curve to use. This can be determined either from a chart (as with traditional jobs), or requested from the DS calculator. In this case, OMICS will request the BC to use from the calculator, as follows:
OMICS creates a file traynum.LDS (or ordernum.LDS) with the REQ=BRS instruction, in the C:\DS\LDS folder
The DS calculator picks up the file, and creates a response
OMICS waits until the traynum.BAS/LMS (or ordernum.BAS/LMS) response file appears in the C:\DS\LMS folder, then reads it in to get the optimum, lower and upper limits for the base curve to use. If the file does not appear with a certain number of seconds (specified on the Digital system variables tab), OMICS times out and cannot select blanks.
OMICS then selects a SV lens with an appropriate base curve (based on the BAS response).
When the job is saved, an entry is created in a file used to queue up jobs to be processed by the Digital Surface Processor. This file (DATA\OMFREEPR.DAT), stores each digital job number as it is entered, and the processor processes the jobs in the sequence they were stored.  When the information on the job is sent TO the digital calculation engine, the entry for the Rx is date and time-stamped.  When a response is received from the digital calculation engine, the results are saved in the order and device files, and the entry removed from the OMFREEPR file.  Thus, the OMFREEPR file should contain only jobs that are currently "in process" between OMICS and the freeform calculation engine.
The OMICS Digital Surface Processor, (DSP) runs in its own session like the Remote Order or Job Track processors.   When the DSP detects an entry in the OMFREEPR file, it creates an ASCII file in VCA format (the LDS file) that it places in the "digital surface TO location" from the corresponding Digital Surface type (C:\DS\LDS in our example).  The DSP monitors the "digital surface from location" of all the Digital Surface type entries; when it detects an entry in one of the "from" locations, OMICS processes the entry received.  OMICS will delete the LMS files once it has been processed.
Note that if a folder named "ARCHIVE" exists under the "out" or "in" folders, the DSP makes a copy of both the LDS and LMS files as they are created or processed.  This is very useful for debugging problems with the interfaces.
The ASCII file that OMICS creates is processed by the Digital Surfacing calculation engine for the digital surface lens type selected.  The calculation engine provides new data regarding the job as well as a file containing the surface cutting information for the generator.  OMICS replaces its job information with the new calculation info received from the Digital Surface Calculation Engine.  The fields that OMICS replaces are associated with the following VCA labels received, BLKD, CRIB, AX, GBASEX, GCROSX, KPRVA, KPRVM, LAPBASX, LAPCRSX, CTHICK, PIND, RNGD,RNGH, THKP, THNP, TIND and FED.  If the Digital Surface Calc Engine sends back info in a different index, then OMICS recalculates the tool curves to 1.530 index.  In most cases, the center thickness sent back by the calculation engine will be different than that calculated by OMICS, so OMICS will recalculate the SET and ACTUAL value for LOH- style blocks.
A calculation engine may calculate a different block size for the job – this also requires recalculating the SET and ACTUAL in order to obtain accurate thickness on the generator.
The differences in the device communications are:

• for all surface jobs on Digital Surface generators
  • GTHK: send generator thickness with no fining allowance (gen thick = finish thickness) - there is no traditional fining step, the generator thickness should NOT include any fining allowance
  • FINCMP: always set to 0 (since fining is not done on these jobs
• for digital surface jobs on Digital Surface generators
  • GPRVM: set prism amounts to 0
  • LNAM: send actual value required by the particular device (entry taken from new field in lens style database)
• for digital surface jobs on surface blockers:
  • AX and GAX:  send 0 for the cyl axis  (because lens is blocked horizontally across reference marks
• for standard surface jobs on an iFlex polisher:
  • GAX:  send 0 for the cylinder axis for surfacing

Be aware that, in the current implementation of digital surfacing in OMICS, it is still possible to retrieve a digital job on a traditional generator - obviously, since the generator is not capable of cutting the back surface topography, you would not get the expected results.  The lab will need to ensure (procedurally) that digital jobs are directed to digital- capable equipment.
Compensated Rx Values (Near-Vision and Wrap Calculations)
Some digital designs (such as near vision designs and wrap designs) will result in a compensated Rx being ground on the lens. In these cases, the lab and dispenser will measure different powers and/or prism than what was originally requested, although the effective Rx will be correct once edged into a frame and placed on the patient's face.
When there is a compensated Rx returned from the digital processor, for whatever reason, OMICS prints the compensated Rx on the work ticket immediately above and below the dispensed Rx, and indicates that it is compensation, for example:  

This is a near-vision style Rx, where the digital processor has returned the Rx to be measured at the near vision point, along with prism that should be present at that point. Results will be displayed in a similar format when wrap compensation is done on an Rx.
Some digital designs may accept (or require) additional parameters from the LMS – particularly panoramic tilt, pantoscopic tilt, and back vertex distance. OMICS already allows entry of these parameters for wrap calculations on non-digital designs, so this has been enhanced to allow entry for a particular lens type. If a particular design should allow entry of these parameters, a flag can be set on that lens style to trigger OMICS to allow entry:

Checking the "Do wrap calcs" box will allow entry of these parameters on the Rx – if specific entries are not made, default values will be used and sent to the digital processor.
8.0 Configuration Specific to Vendors
CrossBows
In the RxInfo.ini configuration file for CrossBows, ensure the following options are set:
LOHComms=0 (this disables the interface with RxServer, which is usually ON by default)
BASExt=BAS (this specifies the extension for BAS responses – OMICS requires this to be BAS, the default is LMS)
InputDir – this should be set to the folder where LDS files will be sent from OMICS, and picked up by CrossBows.
OutputDir – this should be set to the folder where LMS and SDF files will be stored. Note that for SDF files, you should use URL naming conventions, to ensure the devices can find the file when sent in LDPATH.

Essilor
For many designs, Essilor offers the design in regular and short. The LMS is responsible for switching to the short design if the seg height of the order is < X (usually 18mm), and the add power is <= 3.00D. (If the add is > 3.00, the regular design is used regardless of the seg height).
To accomplish this, even though OMICS does not select blanks, the alias file is used to trigger switching between regular and short designs. For example, to set up an alias from Physio Enhanced Azio to Physio Enhanced Azio Short, the lens styles would be set up similar to:

Regular design set up with minimum seg height of 18mm, and maximum add of 3.50


Short design set up with minimum seg height of 14, maximum add power of 3.00
Both styles are set up with the option "LDS selects blanks to use" checked on the Optional tab.
Then set up an alias record from PHEAZ to PHEAZS.
When design PHEAZ is used on an order, OMICS will check the alias file, and will switch to the PHEAZS design if the seg height of the order is < than the minimum specified for the requested design, and if the add power is less than the maximum add power specified on the alias lens style. Multiple alias records can be specified, to allow checking multiple lens styles (ie several corridor lengths).

Zeiss
Zeiss uses an XML-based web service which LMS systems communicate with. The lab will be provided with a URL to connect, as well as a lab ID and password. These settings are unique to each lab and must be set up in the Digital Types entry for the Zeiss calculator.
Zeiss does provide support for base curve requests for some designs, through the web service, so these designs should be set up with the "Use BRS to get BC from DS" option checked. Generally speaking, the AO and Sola designs support BRS requests, while the Zeiss designs do not. The LNAM values can be set up in the lens style, as they do not differ by material, coating, or treatment.
Zeiss digital designs do use Zeiss pucks – not regular SV blanks – so these Zeiss pucks must be set up in the lab's inventory, and the blank selection alias should be set up to alias each design to the PUCK items, similar to:

If you are using Schneider equipment with the Zeiss designs, you will need to manually create sub-folders in the "Location of SDF files from digital surface" location to allow for machine dependent command files that are returned by the calculator.






















The folders are machine dependent and are as follows:
HSC100 for the Schneider HSC 100/101, using example, "DIGITAL\SDF\HSC100"
HSCSMT for the Schneider HSC Smart, using example, "DIGITAL\SDF\HSCSMT"
HSCMST for the Schneider HSC Master, using example, "DIGITAL\SDF\HSCMST"
CCP101 for the Schneider CCP101 polisher, using example, "DIGITAL\SDF\CCP101"
CCP102 for the Schneider CCP102 polisher, using example, "DIGITAL\SDF\CCP102"
When using Schneider equipment, a user-defined VCA label is used to tell the equipment to look for "technology" files in the above folders. Each different model of device should be configured to look at the appropriate folder, so it gets the correct technology file for the device.
Zeiss requires a verification ticket to be printed, by the lab, for each job. This ticket can be printed in two ways – either manually from OMICS, by scanning each tray, or automatically when the job is shipped.
To print these tickets manually (one at a time) from OMICS, select the option from the Closing (Shipping) menu. From the screen (below), scan or enter the tray or order number to be printed.

If the ticket is returned (from Zeiss) as a PDF document, this will be printed first; if the ticket is returned as a TKT file, the Zeiss-provided CZVTKTPRINT.EXE is used to print the verification ticket.
Alternatively, the verification ticket can be automatically printed when the job is shipped. To do this, the printer to print the Zeiss ticket on must be set up. This can be done from within the Workstation Setup screen for the Job Tracker, if only one printer is to be used:

If different printers are used depending on which job station is used to ship the jobs, then the Zeiss ticket printer should be set on the Job Station screen, as follows:
Indo
Indo uses encrypted surface point files for generating their digital designs, but provide a simplified surface point file for devices such as the engraver. The encrypted data is not delivered as a file – rather, it is a security key which is passed to the equipment (in the LDPATH label), and the equipment uses that key to connect to an Indo computer to retrieve the data it needs to generate the design.
As a result, several different paths can be provided by Indo – this is done by means of different LDPATH records, each indicating the device they are intended for. The LMS file will contain something similar to: LDPATH=GEN;;;;;OtqutrrqrsAXagK]IGSn;OuqutrrqrsA[IE[bBixb
LDPATH=ENG;;;;;\\tonydell1\C\DSTransfer\Surfaces\INDO15.SDF
LDPATH=POL;;;;;OtqutrrqrsAXagK]IGSn;OuqutrrqrsA[IE[bBixb
*LDPATH=LMD;;;;;https://192.168.168.4:8011/OtqutrrqrsAXagK\]IGSn.SDF;https://192.168.168.4:8011/OuqutrrqrsA\[IE\[bBixb.SDF*
LDPATH=OtqutrrqrsAXagK]IGSn;OuqutrrqrsA[IE[bBixb
These different LDPATH values will be stored in the PROC file and the appropriate value sent to a device which requests it. This requires a PROC record to exist for the device in question, so if a new device is added that doesn't have a PROC for the device, no LDPATH record will be sent to that device.
Indo lens styles require some optional labels to be set up:
LDTYPE and LDCRYPT are used to tell the generator that Indo-encrypted surface points are being used. The _OPTIM=1 label indicates that thickness should be optimized on the lens.
Some Indo lens designs require NOD (for example) – this can be set up as an optional field on the lens design (as above), with a default value. This value is also settable on each order, on the F12 Surface Options screen:


Indo only supports returning BAS responses as files with an extension of .LMS (other vendors allow an extension of either BAS or LMS). Because of this, Indo must be set up to only process LMS files for jobs which OMICS has submitted, and to look for the BAS response as an LMS file:

If different LNAM values are required for the same design in different materials (as with the Maxima, for example), a label table must be used to set up the correct LNAM values. There is a table named "INDO" available with the web updates; this table looks as follows:

To use the table, specify the table name in the DS setup for the Indo interface:

ProFit
ProFit is a very basic digital calculator – there is no support for BRS requests, so the lab will need to set up base curve charts according to their preferences for each material to be used.
The following designs are available from ProFit (as of Jan 2013):

Note that ProFit uses a combination of LNAM, LDNAM and CORRLEN to identify the design.
CORRLEN can be specified as an optional VCA label on the lens style. For example, the Identity Indoor 16 design would be set up as follows (note the setting of both LNAM and LDNAM):

The optional tab would be set up as:

The LDTYPE entry may or may not be required, but specifying it ensures compatibility when using other LDS systems that may not use SDF files.
Note that ProFit's near vision design (Office+) expects the Rx to be entered as NEAR power in the Rx, and the degression is entered where the ADD power would normally be entered.  This is different than all other near vision LDS designs we have interfaced with to date. 
For the IOFF, which is a near vision digital design, you also need to set LTYP to DG – since DG is not currently one of the recognized VC values for the label, this needs to be set up in the optional labels of the lens style:
9.0 Troubleshooting
The following are common errors which can be returned by the DS processor, and printed on the work ticket (also visible from the F1 device information screen on the order), along with suggestions on how to resolve the issue.
Frame tilt_FaceFormAngle for current design not in range (Lab policy)
One (or more) of the Wrap (panoramic) angle, pantoscopic tilt, or vertex distance, is outside of the range allowed for the design specified.
Below is the chart sent out by Shamir indicating the acceptable levels.

#B;126;Wrong DRILLE Format. The drill eye must be equal to the lens eye;E
We're still working with IOT on the fix for this, but under some conditions the IOT calculator rejects jobs with a DRILLE record, even though the DRILLE record conforms to the VCA standard. The temporary workaround for this is to remove the DRLFMT and DRILLE records from the .LDI file for the IOT design. (This is done in the Digital Type setup for the IOT calculator in OMICS).
8;Object reference not set to an instance of an object; E.
IOT tells me this is a general error message however I encountered this when we tried to send the BRS request to the IOT engine. They are working on this and the work-around for us is to have the lab enter the base curve they want to use into the Stock Screen.
#L;1388: Left-Calculation was terminated because it was found that the lathe will crash into the alloy. This is basically a cutter crash warning from the DS engine. The fix was to select a smaller block.
#R;52827:Right; Failed to insert a new semi-finished blank record because front curvature value is not within the range of any of the available base. The issue here is that they had forced a 0050 base for a job but it wouldn't work; we let Omics pull the lenses and it pulled a 0250 base and that was fine.
#L;1;1back-r too small
The base curve they selected was too high. Once I changed to a lower base the error went away.