Frequently Asked Questions


FAQs for exSILentia

Further Articles

  1. After receiving the online access to exSILentia version 4 "standard". I can not access the LOPA tab as it is greyed out. Is this correct as LOPAX is in the standard tool kit.  
  2. An exida FMEDA report provides two sets of failures for a remote seal - Normal Service and Severe Service. Please can you advise when the "severe service" mode is to be used. It is understood that the remote seals will be designed "fit for purpose" for sp  
  3. Can you explain the difference between SRS and Design SRS?  
  4. Can you explain what does it mean by Digital Out Low Channel and Digital Out High Channel? Is it related with the power of the logic solver?  
  5. Can you please advise if / how Partial valve stroke testing can be applied to valves set as diverse valves.  
  6. Can you please advise if version 2 works in Windows 10?  
  7. Can you please help further clarify “ Online Maintenance”. What does it mean in terms of work to be done on a subsystem (e.g. valve)?​  
  8. Could you explain why increasing the beta factor for 2oo2 will reduce the PFDavg (or increase the RRF) in exSILentia? This is contrary to common understanding. What is the common value used for such architecture?​  
  9. Could you please advise whether the SERH generic data for Skotch Yoke Pneumatic Actuators lambda du of 350 FITs can be considered conservative. What is the basis for the 350 FITs? There are not many of this actuator type in the SERH list to compare to.  
  10. Could you please clarify what the difference between Online/Offline options provided for Sensor and Final Element in exSILentia, in regards to Proof Test Interval. There is no such option provided for logic solver part! In case of choosing "Offline" optio  
  11. Could you please confirm if the exSILentia software is verified / certified by an external body ?  
  12. Could you please confirm the following with regards to verifying the SIL for a Temperature Trip. Can the sensing element (such as the Thermocouple, RTD etc.) be considered as a "passive" from a SIF loop and be ignored from the PFDavg. calculations. This w  
  13. Does the user manual provide enough guidance as to how to handle the exSILentia software without training?  
  14. During a SIL verification process a query was raised as to whether the mission time in the software can be equal to the plant turnaround, or should it be equal to the time from plant start-up to the replacement or refurbishment to as-new condition of the  
  15. For a certain valve, 2 different proof tests with the same valve are required, with a full function test once every 4 years. However the valve is sometimes used during normal operation. This usage during normal operation can be seen as a partial test that  
  16. How can I include two logic solvers (F&G and ESD) in order to verify an entire F&G circuit.?  
  17. How can I make it easier to open windows for SRS? There seems to be a tiny sliver on the right with a > symbol  
  18. How do I perform an "Exclude these beta selections from the report" option from the Beta Factor Estimator to the parameters that can be changed en masse for SILver?  
  19. How does demand rate set to "based on demand rate" change the PFH calculation? For SIFs using sensors, logic solver, and final elements with HFT>0 (with redundancy), how will the high demand calculation for PFH account for changes in the manual proof tes  
  20. How should I model "close riser ESD valve (1oo1) and either well SSV or SDV (1oo2) of 9 wells (9oo9)" using exSILentia? The configuration is written as follows: Close 2oo2 [1oo1 UZV & 9oo9 (1oo2 SSV or SDV)]​  
  21. How to I get a non-empty SIF SRS segment?  
  22. How would I be able to model 2 solenoids in series with 1 valve for the final element. I have a 1oo2 configuration for the solenoids, but only a single valve.​  
  23. I am having trouble modelling the final control element of a SIF loop, having a 1oo2 (with 1oo1, and 4oo4) voting logic. The issue is that in the 4oo4 final control element leg, each component is having different failure rates, therefore I cannot select a  
  24. I can’t find my gap where I get an RRF of 237 but yet don’t even achieve SIL 1 for the a SIF. Can you help explain this?  
  25. I found that the process connection for temperature transmitter is mandatory information for SIL verification but another transmitters are not. Is there is special reason or technical issue for this?  
  26. I have a 1oo1 pressure sensor A. Every year (during the periodic proof test) I can compare this sensor A with another sensor B, which is located further inline. By manually aligning (with the aid of valves) both sensors, I'm capable of doing a compare bet  
  27. I have a 1oo2 of 2 pressure sensors (A and B). Since both sensors are safety relevant, they are connected to the safety PLC. Can I also claim Ext. Comp. for this system? If so, how much coverage can be claimed for it?  
  28. I have a problem trying to create a user defined logic solver. In version 3 you could user define a logic solver so you could use simple devices like a trip amplifier or relay. In Version 4 it looks like I can only select a device that is in the database  
  29. I have a question about MTTR time used in SIL Verification. Is this for the complete mission time duration?  
  30. I have a question about the Application Test Method section of the SIF parameters section in the SILver design tool. Can you provide me with a description of the purpose of this section? I understand that I am able to choose between the IEC61508:2000 or I  
  31. I have a question about the EU Low/EU High sections in the tag section of a sensor group. Is this referring to the signal low/high (2/22 mA?) that will trigger a diagnostic trip for the SIF?  
  32. I have a question about the systematic capability option for equipment in exSILentia. Can this systematic capability parameter can be used for a generic element? If it indeed can be used, how can be set this systematic capability value for a generic eleme  
  33. I have a question on the voting option for final element groups. Would you please explain the meaning and structure of 2oo4 [2oo(1oo2)]?  
  34. I have a question regarding the correct way to simulate voting logic. I don’t understand how different PFD values are calculated if the same voting logic (e.g. 2oo3) are considered within different channels or one single channel.  
  35. I have a question regarding the Diagnostic Coverage Factor; it used to be possible to enter this value in the software for each device - has this feature been removed?​  
  36. I have a SIF that uses a Vegaswing 61/63. This model contains a relay contact which is connected to the triconex tricon DI (discrete input) module. However, exSILentia is showing an AI (analog input) channel being used on the triconex tricon. Shouldn't t  
  37. I have an application with 11 risers from sub-sea oil wells each having dual isolation valves in series, voted 1oo2. I have modelled the scenario assuming four risers and I need help on how to configure a voted group of 11oo11 where each leg has 1oo2 vote  
  38. I have defined a wire as a logic solver (without channels). However the PFDavg for the Logic solver is calculated as 0.0E+0 and the SIF PFD average does not calculate. ​  
  39. I have followed the instruction to create a user defined logic solver but I still have issues that I can’t a simple device such as a trip amplifier because I can’t define any data for the channels for a device such as this. It appears that I have to also  
  40. I have just upgraded to 4.0 and noticed SILver sets my target RRF to 1. Please how do I set the target RRF in version 4.0 using SILver alone (without completing LOPA/Select etc.), such that the target RRF is reflected in the auto generated Detailed SILver  
  41. I installed the latest version of exSILentia 4, but I can't open my original project created in version 3. How can I convert the version 3 project file to be readable from version 4?​  
  42. I just downloaded the new exSILentia V4 and although I can see the CyberPHAx and CyberSL listed in the Modules window under tools, I cannot find how to access the actual tools and I do not see them on the black bar headings in the second line of the exSIL  
  43. I received a "XXYYZZ" Manufacturers Declaration on "XXYYZZ" actuators that has an exida report attached. I haven't been able to find the report on your website. The data in is the exSILentia program but doesn't seem to be certified. Is the data expired  
  44. I requested the SILVER update, and then tried the status button, which said I had not submitted a request.  
  45. I would like to ask how MTTFS is calculated as I am not able to achieve the same results as the software. The failure rates of the sensor are the following: Safe Detected: 1.44E-06 | Safe Undetected: 1.44E-06 | Dangerous Detected: 1.41E-06 | Danger  
  46. I would like to know the main differences between selecting the Application Test Mode of IEC 61508:2000 and the Appplication Test Mode of IEC 61508:2010.​  
  47. I would like to know which tables from 61511:2016 are considered when using this option for architectural constraints in the SIL verification parameters?  
  48. I would like to model 5oo5 final element groups - a prompt is saying to "adjust" the limit of 4 final element groups in "Project Configuration" - however, this parameter is not found in "Project Configuration" - Silver Project Parameters. Is it possible t  
  49. I'd like to select "none" on the process connection on a temperature transmitter, but this option is not available. Why do I have to select the thermocouple or -2/3- wired..something when it comes to the temperature transmitter alone?  
  50. I'm attempting to use "check for updates" to download Silver version 4 and getting error "The server name or address could not be resolved".  
  51. I'm getting an error message 'xxxx' is not a valid value for this property. Valid values are from Int32.MinValue through Int32.MaxValue.  
  52. I'm unable to open exSILentia 3 files using exSILentia 4 - Conversion Failed. Unable to access exida Equipment Database  
  53. I'm using SILver to verify the SIL level of some existing installations. There's a lot of old instruments so when there's no other option, I have to use the generic data. The PFDavg and architectural constraints are good, but logically the systematic capa  
  54. I'm working on a project where the logic solver is a SIL 2 Allen Bradley ControlLogix system with redundant processors and redundant (1oo2) IO. I do not see any Allen Bradley or Rockwell Automation logic solvers in the equipment database. Nor do I see any  
  55. I've been reviewing some SIF verification calculations in exSILentia and I was hoping you could advise on how the software determines the failure rate from manually inputted failure rate data?  
  56. If a sensor is put on a soft maintenance bypass, would that be considered as an online maintenance?  
  57. If maintenance is carried out during the time while the subsystem (e.g. valve) is in service, would that time be captured in verification calculations using MTTR?  
  58. If the Partial Stroke test is done in "Manual" mode, the architectural constraint limits the SIL level to "1", whereas - If the Partial Stroke test is done in "Automatic" mode, the architectural constraint meets the SIL level "2" requirement. Could you pl  
  59. If the time used for proof test for the SIF subsystems has any connection with MTTR, is the MTTR counted independent of the time used for Proof Test Interval? ​  
  60. In a report with an On/Off valve with the accessories MTL-4521, ASCO SOV, Emerson Actuator, and OMS Ball Valve, all the accessories are individually meeting SFF of above 70% but the overall SFF is coming to be 54%. Can you explain this please?  
  61. In order to meet Target SIL 3, we have to apply PVST (Automatic; Interval 3 Months; Coverage 80%) for both valve groups. This means if I input ESD as an interface module for Valve 2, it looks like ESD is also diagnosed by PVST; (Actually, ESD is not relat  
  62. In our project, there is a Local Panel from which after every 3 months operator will press the Start PST push button and it will execute the PST automatically thereafter. In such a scenario​ can we consider PST to be automatic and take credit for it or do  
  63. In our setup, for the valve PST, smart positioners have been installed. A test is initiated from DCS Station by operator. The test results are automatically captured in the AMS (Asset Management System). Could you please help confirm if the setup in plac  
  64. In regards to MTTR, does the value refers to the complete duration while the SIF is in service i.e. the testing of a subsystem as well as any other maintenance being carried out on a subsystem?  
  65. In the new version of the software, we've had a problem related to the beta factor in the Final Element. Usually, when the Beta factor is increased, the PFD is increased too. But in this version, it happened the other way around. It only happens in the fi  
  66. Is it possible to select the HFT constraints routes, subsystem wise, instead of applying it only to the whole SIF? i.e. Route 2H-61508 for “S”, Route 1H-61508 for “Logic Solver” and clause 11.4.5 IEC61511 2nd edition for “Final Element”​?  
  67. Is it possible to set up 2 (or more) different proof tests at different frequencies each with different %age coverages for 1 SIF?  
  68. Is there a way to add conditional modifiers (such as probability of ignition, occupancy, etc) and/or time at risk to the LOPA assessment​?​  
  69. I’ve copied the parameters from a supplier in SILver, but I don’t understand why the PFDavg value calculated in SILver (3.10E-02) is different to the value in the manufacture datasheet (8.76E-04) for Sensor TMT82 of Endress+Hause for 5 years? 1oo1, theref  
  70. Occasionally I experience performance issues when using the online version, with navigation between menus being slow or even frozen.  
  71. Please advise silent installation procedure or addition code / methodology for silent software installation.  
  72. Please can you advise how the safe failures are calculated for a final element with partial stroke testing?  
  73. The Achieved SIL box is not updating. An example is where the SIL 2 has been calculated/achieved but the SIL Achieved box shows 0. Not sure if this is an error I am making or a software problem. Please advise.​  
  74. The calculation of PFD shows a discrepancy between the exSILentia and ISA formulas. Would you be kind enough to share the formula used in exSILentia so we may compare and note what are the differences and evaluate ISA formula accordingly.  
  75. The exida LOPA database did not install on the user's system. Can you provide instructions/download for the database?  
  76. The exSILentia database includes failure rates for Industrial PLC that has the remark that the data reflects a high-end general purpose PLC like ControlLogix. The Allen Bradley safety reference manual on Using ControlLogix in SIL 2 applications states tha  
  77. The SERH data for a Fisher Control DVC6200 SIS DETT lists the device type as Type A, which means it should be a simple mechanical non programmable device. However as the DVC6200 SIS has a micro controller cum processor built in which can be programmed for  
  78. This refers to the Generic 2/3 Wire RTD Configurations in exSILentia. We find that the Generic 2/3 wire RTD close coupled, Low stress lamda du = 173 and RTD Extension wire, Low stress lamda du =95. This data points in the direction that close coupled is b  
  79. We have 2 related Logic Solvers in one SIF. When the Steam Turbine Speed is High High, our SIF closes steam line 2 valves to protect the compressor. One valve is closed via PLC 1 (Invensys Trident, 2oo3 TMR) and the other is closed via PLC 2 (Honeywell SM  
  80. We have a 4oo4 final element. We realised that when we increase the beta factor the probability of failure on demand decreases. How is it technically possible? Theoretically, when the the beta (common failure mode) is increased, the PFD should decrease?​  
  81. We have a conceptual design where we would like to model 9 “output groups”. For each of the 9 output groups, we would like to include a 1oo2 valve assembly (identical), i.e., redundant valve assemblies (including 1oo2 solenoid valves on each valve, the ac  
  82. We have a pressure transmitter with an SFF> 90% that we use in a SIL 2 with an HFT of 0 (see table 2 and 3 IEC61508-2). Then a Intrinsic Safety Isolated Barrier is also included in this loop (P&F). When we enter these 2 devices into exSILentia, the SFF de  
  83. We have a SIF with 5 streams (each stream with 1oo2 shutoff valves) that trips all of the valves on these 5 streams in case of an event. How do we configure this SIF voting?​  
  84. We have a SIF with the dual temperature elements (RTD) and one temperature transmitter with hot backup function. Can we use a separate SIF to get the failure rates of 1oo2 voting of sensor parts for dual RTD and fill this calculated failure rates into the  
  85. We have a situation where a proof test coverage of 95% on the final element part of a particular SIF is being claimed. The final element part consist of a solenoid valve and separate actuator and valve. Tight shut off is not necessary. Is this credible? H  
  86. We have an issue regarding the IEC 61511 compliance report. We generated 2 reports on different times but with the same data. In the first case we got a SFF value of 80.1 for our final element in a SIF. When we generated a new report the SFF value has bee  
  87. We have one set of 1 Transmitter and 1 IS Isolator. I approached this in 2 different ways. Option 1) transmitter + IS Isolator in Sensor Group 1. Option 2) Transmitter in Sensor Group 1 + IS Isolator in Sensor Group 2. The PFDavg were same between Option  
  88. We need to do the SIL Verification of a safety loop which does not include a PLC but goes from the sensor to the final element through direct cabling (TT which stops a motor). How can we do this?  
  89. We need to simulate a trip which is 3FT in a 2oo3 voting and compensated by pressure and temperature by a PT and TT for each FT. How can we proceed?  
  90. We noticed there is a difference when we use a 1oo2 voting for 2 redundant measurements as a leg, or as a group. exemple 1: TT1 1oo1 1oo2, TT2 1oo1. exemple 2: TT1+TT2 1oo2 1oo1. Which is the correct one? why is it and what is causing the difference in fa  
  91. We would like to perform a Verification with a Full Stroke Test in a valve. It is possible to include this consideration in the Verification.?  
  92. When a colleague or I try to login, we are able to login but then get a blinking screen. We tried both IE and Chrome and got the same result.  
  93. When constructing a SIF consisting of a sensor, trip evaluator/transducer (PR 4116), a safety relay and a valve (no safety PLC), I get different PDF values depending on if I define the PR4116 as an interface to the sensor, compared to if I define it as pa  
  94. When creating new SIL verification calculations it appears I can only select logic solvers from 'EDB' as opposed to adding my own failure rate information.  
  95. When generating the SILlver summary report or detailed report - this is an "error" shown in word viewer -cannot open file. The Silver detailed report does give options to select which SIFs (or all) to report.​  
  96. When I go to C:\Program Files (x86)\exida\exSILentia 4​ (the default install location), I see two files: exida.lopadb and generic.lopadb, but both have the size of 1kB with today's date. I doubt they are not the correct database. For reasons that I do not  
  97. When I logged in first thing today onto my computer I was able to successfully access the software. I then logged off and went to a computer in a meeting room where I had a workshop scheduled and needed to access a screen projector. When I logged into thi  
  98. When I open a PHA file through my coworker's account on my computer the file has no data in it. The PHA and LOPA tabs are not present. When my coworker opens the file through his account on his computer, the file is present with all the data​.  
  99. When I purchase the exSILentia tool is the Safety Equipment Reliability Handbook included or is there extra cost?  
  100. When I switch between the 2000/2010 application test methods and man/auto applications (and PVST) testing, the result changes. I would expect the manual in 2010 to provide the same result as manual/auto in 2000 mode. On the final element, enabling the par  

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