Rockwell Automation 1757-SWKIT3200 ProcessLogix R320.0 Installation and Upgrade Guide - Manual (Page 255)

Publication 1757-IN032B-EN-P - April 2001
Performance and Capacity Specifications 7-15
Input Module Sample Periods
Output Module Sample Periods
ATTENTION
!
Avoid operator-induced redundant controller
switchovers with I/O that is configured but not
physically present. In a redundant controller, the new
primary 1757-PLX52 infrequently may become mute
or hard fault under stress test conditions involving both
{1} a non-trivial number of repetitive switchovers and
{2} I/O configured in the controller that is not
physically present. The only recovery is to power-cycle
the mute of faulted primary controller.
Table 7.R Input Module Sampling Period Specifications
Module types Sampling period
Typical Input Module
Includes 1757/1756 input modules 1797-FLEX Ex and 1794-FLEX I/O
input modules, and CN2FFs with exceptions noted below 25 ms
High Density / Non-Isolated Analog Input Module (1756-IF16) 250 ms
RTD Module (1756-IR6I) 50 ms
Thermocouple Module (1756-IT6I) 50 ms
TC-MUX021 250 ms
Digital Input Module used by 5 ms (local only) 1 ms
Note: For CMs which contain associated input channels, it is recommended that the CM execution
period should be set to at least double the input module sampling period.
Table 7.S Output Module Sampling Period Specifications
Output Module Sampling Period Specifications
Module Type Sampling Period
Typical Output Module
1757/1756 +1797 FLEX EX and 1794-FLEX I/O Output Modules 50 ms