Rockwell Automation 1769-OF2 Compact I/O Analog Modules - Manual (Page 79)

Publication 1769-UM002B-EN-P - July 2005
Module Data, Status, and Channel Configuration for the Input Modules 3-29
1769-IF8 Real Time Sampling
This parameter instructs the module how often to scan its input channels and
obtain all available data. After the channels are scanned, the module places the
data into the Input Data file. This feature is applied on a module-wide basis.
During module configuration, you specify a Real Time Sampling (RTS) period
by entering a value into Word 0 of the Configuration Data file. This value
entered in Word 0 can be in the range of 0 to 5000 and indicates the sampling
rate the module will use in 1 ms increments.
If you enter a 0 for the Real Time Sample Rate, the module should scan its
inputs at as fast a rate as possible, controlled by the number of enabled
channels and the filter setting selected for those channels.
The module compares the Real Time Sample Rate value entered in Word 0 of
the Configuration Data file with a calculated module update time, again based
on the number of enabled channels and the filter setting selected for those
channels. If the value entered for the Real Time Sample Rate is smaller than
the calculated module update time, the module indicates a configuration error.
The longest Real Time Sample Rate supported by the 1769-IF8 is 5 s, the
maximum value for Word 0 of the Configuration Data file is 5000 decimal.