Performing autoćcalibration, Offset calibration – Rockwell Automation 1771-IXE/D Thermocouple/Millivolt Input Module User Manual User Manual
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Module Calibration
Publication 1771Ć6.5.130 Ć May 1999
Calibration of the module consists of applying 0.000mV across each
input channel for offset calibration, and +100.000mV across each
input channel for gain correction.
Offset Calibration
Normally all inputs are calibrated together. To calibrate the offset of
an input, proceed as follows:
1. Apply power to the module.
2. Connect shorting links, or apply 0.000mV across each input
channel on the 1771–WI field wiring arm as shown in Figure 6.1.
Figure 6.1
Shorting Inputs for Offset Calibration
1
Do not
use
18
Input 1 (+ lead)
17
Input 1 (- lead)
16
Input 2 (+ lead)
15
Input 2 (- lead)
14
Input 3 (+ lead)
13
Input 3 (- lead)
12
Input 4 (+ lead)
11
Input 4 (- lead)
10
Not Used
9
Not used
8
Input 5 (+ lead)
7
Input 5 (- lead)
6
Input 6 (+ lead)
5
Input 6 (- lead)
4
Input 7 (+ lead)
3
Input 7 (- lead)
2
Input 8 (+ lead)
1
Input 8 (- lead)
Terminal Identification
Terminal
Function
Wiring Arm
Cat. No. 1771-WI
18
17
16
1
15
14
13
12
11
10
9
8
7
6
5
4
3
2
Repeat for each channel
Apply
0.000mV
Short each input,
or apply 0.000mV
across each input
channel.
Shorting link.
10530-I
3. After the connections stabilize, request the offset calibration by
setting bit 00 in block transfer write word 28 and sending a block
transfer write (BTW) to the module. Refer to Table 6.A.
When the BTW is sent, all channels are calibrated to 0.000mV.
Performing
AutoĆCalibration