Rockwell Automation Allen-Bradley 1769-IF4, Руководство пользователя

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Publication 1769-UM002B-EN-P - July 2005
3-26 Module Data, Status, and Channel Configuration for the Input Modules
If you use real-time sampling, the user-configured sample rate is used as the
module update time.
Examples of Calculating Module Update Time
Table 3.16 Filter Frequency and Update Times
Filter Frequency Update Time per
Channel
Update Time per
Module
(1)
(1)
Module update time applies if you use all channel pairs and all enabled channels, and all the
enabled channels use the filter frequency from the first column.
10 Hz 100 ms 400 ms
50 Hz 30 ms 120 ms
60 Hz 30 ms 120 ms
250 Hz 9 ms 36 ms
500 Hz 6 ms 24 ms
EXAMPLE
1. Two Channels Enabled with Identical Filter Setting, But Not a Channel Pair
The following example calculates the 1769-IF8 module update time for two channels enabled with
any configuration and a 500 Hz filter but the enabled channels are not a channel pair.
•
Channel 0: ±10V dc with 500 Hz filter
•
Channel 1: 0…10V dc with 500 Hz filter
Module Update Time = [Greater of Channel 0 Update Time or Channel 4 Update Time]
+ [Greater of Channel 1 Update Time or Channel 5 Update Time]
12 ms = [Greater of 6 ms or 0 ms] + [Greater of 6 ms or 0 ms]