Rockwell Automation 1769-IF4XOF2 Compact 8-Bit Low Resolution Analog I/O Combination Module - Manual (Page 57)

Publication 1769-UM008A-EN-P - November 2001
1769-IF4XOF2 Module Data, Status, and Configuration Channels 4-13
Module Input Update Time and Scanning Process
The module input update time is defined as the time required for the
module to sample and convert the input signals of all 4 enabled input
channels and provide the resulting data values to the processor.
Module update time can be calculated by adding the sum of all
enabled channel times. Channel times include channel scan time,
channel switching time, and reconfiguration time. The module
sequentially samples the channels in a continuous loop. The table
below shows module update times, based on the number of input
channels enabled.
Maximum Input Response Time of Module (5 ms)
Minimum Input Response
Time of Module (5 ms)
Input Signal
Input After Filter
A/D Conversion (4 CH)
MPU/ASIC Input Data
Communication
MPU/ASIC Output Data
Communication
Output D/A Conversion
Input Update Time (4.5 ms)
Table 4.8 Module Update Time
Number of Enabled Input Channels
Typical Update Time
(1)
(1) Each enabled output channel adds 0.02 ms to the typical module update time.
0 1.3 ms
1 2.1 ms
2 2.9 ms
3 3.7 ms
4 4.5 ms