Output Calibration 
298  UDC3500 Universal Digital Controller Product Manual  3/07 
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  Action 
1 
Apply power and allow the controller to warm up 30 minutes before you calibrate. 
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. 
 
 
Milliammeter
 
+
 
+
21
20
22
23
24
25
26
27
19
Curre nt 
Out
ut 2 
 
Figure 6-2  Wiring Connections for Calibrating the Second Current Output