Rockwell Automation 1715-OF8I Redundant I/O System User Manual - Manual (Page 240)

240 Rockwell Automation Publication 1715-UM001C-EN-P - March 2014
Chapter 7 Using SIL 2 Add-On Instructions with 1715 Redundant I/O Modules
8. Create a tag with the appropriate Add-On Instruction data type for the
Requested Output Data.
9. Enter the module RPI.
To optimize system bandwidth, type the same RPI value from the module
configuration.
Add-On Instruction Scan Times
Safety Reaction Time Calculations
The 1715 AOIs process data at a rate of the module RPI / 2. For example, if the
1715-IF16 RPI = 100ms, the 1715 IF16 AOI will process the most recent packet
every 50ms. This provides a compromise between controller bandwidth (not
processing the packets too often using old data) and overall 1715 screw to screw
performance. Because the 1715 AOIs run on a time basis, the input module AOI
and the output module AOI can be asynchronous. See page 231 for additional
Table 47 - Maximum Scan Rates Measured
Module Add-On Instruction Scan Rate µs (max measured)
1715-AENTR AENTR_SIL2 Duplex 455
1715-IB16D IB16D_Simplex_SIL2 Simplex 340
1715-IB16D IB16D_Duplex_SIL2 Duplex 378
1715-IF16 IF16_Simplex_SIL2 Simplex 831
1715-IF16 IF16_Duplex_SIL2 Duplex 832
1715-OB8DE OB8DE_Simplex_SIL2 Simplex 501
1715-OB8DE OB8DE_Duplex_SIL2 Duplex 541
1715-OF8 OF8I_Simplex_SIL2 Simplex 951
1715-OF8 OF8I_Duplex_SIL2 Duplex 964
N/A CRC Calculator N/A N/A