Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual - Manual (Page 38)

Publication 1746-UM026A-EN-P - September 2003
4-14 Configuring the Module
The low clamp limit value must be lower than the high clamp limit
value.
EXAMPLE 2: Output Clamping
Suppose you have a valve connected to Channel 0 with a ±10V
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 word:
Suppose, also, that you would like to set the output limits to -2V
and +8V. You would enter the following for Channel 0 data
parameters 1 and 2:
O:e.16 Value = -2000 decimal (-2V)
O:e.24 Value = 8000 decimal (+8V)
Now, by setting bit 8 and 10 in the Channel 0 configuration word,
the output will be clamped to -2 to +8 volts.
Monitor bit 1 of Channel 0 Input Status Word 2 (I:e.8). When the bit
is 1 (clamping values set) then set the Channel 0 configuration back
to its original value.
Your Channel 0 data output will now look like this.
TIP
For some ranges and formats, the clamp alarms will
occur a few counts from the set clamping values.
This means you may need to command an output
value lower or higher than the output clamping
limits in order to get output at low/high clamp
alarms.
Address 15 Channel 0 Configuration Word 0
O:e.8 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1
Address 15 Channel 0 Configuration Word 0
O:e.8 0 0 0 0 0 1 1 1 0 0 0 1 0 0 0 1
Address 15 Channel 0 Configuration Word 0
O:e.8 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1