Output Calibration
6.3 Second Current Output Calibration
Introduction
Calibrate the controller so that the output provides the proper amount of current over the
desired range. The controller can provide a current output range of from 0 mA to 21 mA.
The controller is usually calibrated at 4 mA for 0 % of output and 20 mA for 100 % of
output, but it may be calibrated for any other values between 0 mA and 21 mA. It is not
necessary to re-calibrate the controller in order to change from 4 to 20 mA operation over
to 0 to 20 mA operation, a simple configuration change is all that is required. See the CO
RANGE configuration for Second Current Output in Sub-section 3.22 for details.
Equipment Needed
You will need a calibrating device with whatever accuracy is required, capable of
measuring 0 to 20 mA.
Calibrator Connections
Refer to Figure 6-2 and wire the controller according to the procedure given in Table 6-3.
Table 6-3 Set Up Wiring Procedure for the Second Current Output
Step
Apply power and allow the controller to warm up 30 minutes before you calibrate.
1
2
Set LOCK in the Tuning Set Up group to NONE.
3
Tag and disconnect the field wiring, at the rear of the controller, from terminals 24 (+)
and 25 (–). See Figure 6-2.
4
Connect a milliammeter across these terminals.
Figure 6-2 Wiring Connections for Calibrating the Second Current Output
298
19
20
21
22
23
24
Curre nt
Output 2
25
26
27
UDC3500 Universal Digital Controller Product Manual
Action
Milliammeter
+
+
_
_
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