Rockwell Automation T7420A_AF ICS Regent+Plus Analog Input Modules 60Hz Rejection and Fast Response - Manual (Page 19)

Analog Input Modules (T7420A, AF)
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help you determine the frequency for checking the
calibration of the modules in your installation.
Calibration Methods
Calibrating the analog input module requires that you
connect calibration voltages to all of the analog input
channels of the module and adjust the trimming
potentiometers until the analog inputs read the correct
calibration values. During calibration the module must be
installed in a Regent system and disconnected from the field
signal wiring while the calibration voltages are connected to
the module input signals.
There are three trimming potentiometers which are accessible
through the front face of the module making calibration
adjustments possible without opening the module’s cover.
However, the corresponding field wiring will have to be
disconnected from the I/O chassis terminals.
If you do not wish to disturb the field wiring during
calibration, the I/O Extender module (catalog T3322), can be
used. With the analog input module PCB removed from the
module housing and plugged into the I/O extender module,
you can connect the calibration voltages to the I/O extender
module and leave the analog input field wiring in place. This
is the recommended method for calibrating the analog inputs.
and is described below in the calibration procedure.
Calibration Procedure
Equipment Required
· DC signal source with a range from -10 VDC to +10 VDC @
10 mA minimum and with an accuracy and resolution of
better than 100
m VDC.
·
Potentiometer adjustment tool.
· Phillips screwdriver
· I/O module extender, catalog number T7322
(recommended).
· PC running the W INTERPRET software, used to monitor the
analog input channel values during calibration.