History of changes of SILcet

SILcet 5.1

Improvements in SILcet 5.1:
  • New option to select in each SIF if the analog transmitter fault diagnostics are implemented in the PLC and in what way. There are 4 possible selections:

-Diagnostics implemented in the PLC (analog signal “out of range“): ON-OFF (or option disabled if the sensor is digital or for other reasons).

-Process Trip: High or Low

-Transmitter Fault: Over-Range (> 20mA) or Under-Range (<4 mA). To define how the transmitter has been configured.

-Channel Trip: Yes-No-never.

  • Possibility of automatically showing these selections in the Report.

This new version 5.1 will be available on October 7th, 2020.

(Go to SILcet Prices for more information about versions)

SILcet 5.0.3

Major Improvements in SILcet 5.0.3:
  • Sheet “SIL”: Now it’s possible to enter directly in SIF Table the “parts” of each subsystem. Example for Sensor Subsystem: Process connection, Transmitter and Interface (The Excel macro adds the failure rates of the parts). This makes data entry much easier, and it greatly improves the quality of the report.
  • Sheets “SIL” & “CF”: Now we can use formulas in the failure rates cells (range K:S).
  • Sheet “SIL”: General architecture “MooN” has been included to be able to calculate special architectures such as 1oo8, 2oo24, or any other. Due to this, the general architecture 1ooN has been removed.
  • A deep update of the USER MANUAL has been carried out.
Other improvements in SILcet 5.0.3:
  • Sheet “SIL”: Column S is used to calculate Cpt value of the subsystem based on Cpt & DU Failure Rates of the parts.
  • Sheets “SIL” & “CF”: Method A to calculate STR/MTTFS has been removed because it’s a too simple method. Method B is now the method of calculation which gives results very similar to exSILentia tool. MTTFS formulas of architectures 2oo4, 2oo5, 3oo4, and 4oo5 have been updated.
  • Macros “CopySIF” & “Import” have been improved.
  • Sheet “SIL”: Default value of HFT for architectures 1oo2R, 2oo2S and Kx1oo2 has been changed to 2 (instead of 1). User can changed.
  • Added architecture 2oo4D for Logic Solver.
  • Sheet “SIL”: For Report 1 added label option “Group” to print SIFs marked with “Group” in a different way (only data tables).
  • Headers of sheets “sensor, logicsolver, actuator, other” have been updated. New columns (R:S) has been added for Route and Cpt value.
  • The sheets “sensor, actuator” have been expanded to 100 rows. The sheet “other” has been reduced to 40 rows.
  • Sheet “SIL”: it is possible to manually enter the MTTFS value even if we automatically calculate the PFDavg value.

(Go to SILcet Prices for more information about versions)

SILcet 4.1.1

Improvements in SILcet 4.1.1:
  • New macro C3 to generate up to 10 lists of the selected SIFs in order to compare different configurations, for example by introducing different correction factors of the main parameters (failure rates, Cpt, TI, LT, Beta, MTTRdd, MTTRs). This function can be used to compare different scenarios of effectiveness in maintaining the SIFs of the project.
  • Updated the user-form of the macro C2 to show more information about the SIF sensitivity results. Small modifications have been made to the format of the sheet C2.
  • The reports show which route has been used in each SIF (Route 1H or 2H).
  • In column AL of the sheet “SIL” you can select the architecture “–” to have the option of not showing the architecture and other data in some positions of the R1 report.
  • Function “IMPORT”: Table D.5 and Table 2 of the sheet “SIL” have been added, as well as the U1-U2-U3 sheets.
  • All cells on sheets Sensor, Logicsolver, Actuator and Other have been unlocked.
  • A simple Excel is included to calculate the Cpt value of the actuator subsystem.

(Go to SILcet Prices for more information about versions)

SILcet 4.0.5

Improvements in SILcet 4.0.5:
  • A message has been added when the Cpt value of the SIF is lower than the PDo value of column AB on sheet SIL. The columns AB: AD are used to calculate the PFDavg value when we perform functional tests without stopping the process (see the User Guide).
  • With the “CopySIF” function, the formulas and format of the g:ac range of the SIL sheet are also copied (see the “Analysis of SIF behavior” section of the User Guide if the sensitivity of the SIF is analyzed when modifying Cpt with SILcet Pro Plus version).
  • With the “Import” function, the formulas in the range ab:ac of the sheet SIL are also copied.

(Go to SILcet Prices for more information about versions)

SILcet 4.0.4

Major improvements in SILcet 4.0.4:
  • Calculation of PFDavg with online proof tests (without stopping the process). For example in the case of performing the Partial Stroke Test (PST), every 30 to 60 days, without a process shutdown, and the Full Stroke Test (FST) during the maintenance overhaul. In this way it is possible to increase the TI value (time between plant overhauls). The calculation is based on the formula recommended in ISA TR84.00.03.

(Go to SILcet Prices for more information about versions)

Other improvements in SILcet 4.0.4:
  • Warning message in each SIF when route 2H is used and the value of DC (diagnostic coverage) is less than 60% in type B elements (according to IEC61511: 2016).
  • MooN architectures (M different than N): Option to calculate, on the “SIL” sheet, the value of PFDavg considering all the terms of the MTTRdd parameter. These terms are usually very small and do not affect the value of PFDavg in architectures such as 1oo2, 2oo3, 1oo3, etc. The practical use of this option is to analyze the impact of the MTTRdd parameter in the event that the repair time is too long and the process has not stopped when the dangerous failure is detected.
  • Minor modifications: it includes the import of the values of the “Site Index” in the macro “Import”, modified the user-form “Other” of the sheet “SIL2″, corrected the cell refresh bug in the macro of the sheet ” C2 “.

SILcet 4.0.3

Major improvements in SILcet 4.0.3:
  • Extended the number of SIFs up to 70 in SILcet 4.0.3 Pro Plus.

(Go to SILcet Prices for more information about versions).

Minor improvements in SILcet 4.0.3:
  • Added column AA on sheet “SIL” to be able to multiply the calculated values of PFDavg (or PFH) and STR by a factor. This can be used to calculate the impact of bypasses in redundant architectures and other cases (e.g.: 2oo3 is degraded to 2oo2 to make an online test).

SILcet 3

Major improvements SILcet 3.0:
  • One more option for the SIL rating (“SIL Calculator“) has been added to calculate the SIF of the Safety Functions. This new option is easier to use and solves 90% of the architectures found in the industry. The SILcet sheet “SIL2” should be used, either by working directly on the cells of the sheet or by opening the “user-form” using the blue button “Calculator”. The calculation formulas used are the same as those used in the “SIL” sheet, based on IEC-61508/61511.
  • In this new version, it can be selected in each SIF between the low demand (PFDavg) and the high demand (PFH) mode. In both cases, the formulas used are based on the recommendations of IEC-61508. There are 21 types of architectures available for calculating the PFDavg and 8 types for PFH.

(Go to SILcet page for more information).

Minor improvements:
  • Added new 1ooM architecture (M is changeable by the user).
  • Added new “Import” function to copy the contents of the 35 SIFs of the “SIL2” sheet from another SILcet file, for example, it can be used to import the configuration used in previous versions of SILcet.
  • In this version 3.0, formulas can be entered in the 12 cells of the SIF of the “SIL” sheet where the results of PFDavg / PFH and MTTFS (columns AM and AS) are shown. The formulas are not modified when the calculations are updated (with the “Update” button) if “Pfd” has been selected in column G. This function is useful when intermediate calculations of the “CF” sheet are used in the case of very complex configurations.
  • The graph colors on the “Graphs” sheet have been modified to be the same as those used in the “Compare” function.
  • A second chart format has been added to the “Graphs” sheet (only showing the values ​​of PFDavg / PFH) that can also be selected in the reports.
  • Modified and added some help comments in the cells.