Rockwell Automation T3420AF ICS Regent Analog Input Modules - Manual (Page 34)

Analog Input Modules (T3420A, AF)
3 4
Industrial Control Services
4. Connect the DC voltage signal source to the I/O extender
jumper posts as shown in Figures 20 or 21. Use test clips
as required to make the connections.
5. Remove the four screws on one side of the module and
remove the printed circuit board from the module
clamshell housing.
6. Install the printed circuit board into the I/O extender
module. Allow the board to warm up for approximately one
minute.
7. Adjust the DC voltage source to the Offset Input Voltage
value indicated in Table 6 for the configured input range
of the input module. Wait approximately one minute for
the analog inputs to stabilize.
8. Using the monitoring functions of W INTERPRET , monitor
the values of all the analog input channels. Refer to the
Regent User’s Guide for more details about the monitoring
functions.
9. Adjust the Offset potentiometer (R569) for an average
reading of 2 ±1 for all input channels. Verify that all input
channels read between 1 and 3. If one or more channels
reads significantly different, return the module to ICS for
repair.
10. Adjust the DC voltage source to the Gain Input Voltage
value indicated in Table 6 for the configured input range
of the input module. Wait approximately one minute for
the analog inputs to stabilize.
11. Adjust the Gain potentiometer for a reading of 4093 ±1 for
all channels. Verify that all input channels read between
4092 and 4094. If one or more channels reads significantly
different, return the module to ICS for repair.
12. Repeat steps 7 through 11 and make adjustments if
necessary until both the Offset and Gain values read
correctly. There is some interaction between the Offset and
Gain adjustments so often you will need to repeat these
steps a few times until both the Offset and Gain readings
read correctly without further adjustments.
13. Calibration is complete. Unplug the printed circuit board
from the I/O extender module and replace it in its