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Rockwell Automation Publication 1756-UM540E-EN-P - December 2017
Chapter 5
1756-OF8I Isolated Analog Output Module
Multiple Output Ranges
The 1756-OF8I module offers multiple output ranges that are dictated by
channel configuration choices. The output type selection determines the
available ranges.
To see where to select the output range, see
.
Channel Offset
With this feature, you can compensate for any known error on the sensor or
channel to which the sensor is connected. This value is in engineering units and is
added to the output data.
You can set the channel offset in either of the following ways:
•
On the Configuration tab of the Module Properties dialog box.
•
Directly in the channel’s
C.Ch[x].Offset
tag.
For example, if the channel has an error such that it reads 8 mA as 7.8 mA, you
account for the error by setting the Channel Offset field on the Configuration
tab to 1.2500 if using the default scaling of 4…20 ma = 0…100%, or by setting the
C.Ch[x].Offset
tag to 1.25.
To see where to set the Channel Offset, see
Ramping/Rate Limiting
Ramping limits the speed at which an analog output signal can change. This
prevents fast transitions in the output from damaging the devices that an output
module controls. Ramping is also known as rate limiting.
Table 20 - Channel Output Ranges
Output Type
Output Range
Current (mA)
0…20 mA
Voltage (V)
Any of the following:
•
-10…10V
•
0…5V
•
0…10V