Rockwell Automation 1746-NO8V SLC 500 8-Point Analog Output Module/ User Manual User Manual
Page 37
Publication 1746-UM026A-EN-P - September 2003
Configuring the Module 4-13
Now set the bits in the Channel 0 configuration word to define the
user-scaling values.
Monitor bit 0 of Channel 0 Input Status Word 2 (I:e.8). When this bit
is 1 (user scaling values set), then set the Channel 0 configuration to
be User-Scaling.
When the user-defined scale values are set and the user-defined
scale data format is selected, the relationship between data value
(counts) and output signal is as follows:
Figure 4.3 Example relationship between output signal and channel data
Output Clamping
For added safety, the 1746-NO8I and 1746-NO8V output modules let
you define limits for the values in the output data words individually
for all eight channels. These data limits, in turn, limit the output
signals. 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.
The low clamping limit (Output Data Parameter 1) is the value which
the output signal will not go below. The high clamping limit (Output
Data Parameter 2) is the value which the output signal will not go
above.
Address
15
Channel 0 Configuration Word
0
O:e.8
0
0
0
0
0
0
1
1
0
1
0
0
0
0
1
1
Address
15
Channel 0 Configuration Word
0
O:e.8
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
1
100
9999
20.5 mA
3.5 mA
Data Value
O
ut
pu
t Sign
al