Output Data Limits - Spectrum Controls SLC 500 User Manual

Chapter 3: Configuring the 1746sc-INO4I 3-9

Output Data Limits

For added safety, the 1746sc-INO4i and 1746sc-INO4vi output modules let you
define limits for the values in the output data words of all four channels. These
data limits, in turn, limit the output signals that your module provides. When an
output data word exceeds the data limit, the output value is truncated to the limit.
You can use output data limiting to prevent PID loops from exceeding safety
limits, to prevent operators from inadvertently setting incorrect values, etc.
To properly enable output data limiting, the low and high output limits (output
words 6 and 7, respectively) musts be non-zero and non-equal, and the low limit
(output word 6) must be lower than the high limit (output word 7).
Example – Suppose you have four valves with a ±10 V operating range, and you
want to use the Engineering Units data format. For this application, you would
use the following bit settings for the channel configuration bytes (output words 4
and 5):
Suppose, also, that you would like to set the output limits to -2 V and +8 V. After
entering the above bit settings for output words 4 and 5, you would enter the
following for output words 6 and 7:
User's Manual Pub. 0300266-04 Rev. A