Rockwell Automation Allen-Bradley 1794-IRT8K, User Manual

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Publication 1794-6.5.12 - September 2011
Calibrate Your Module
45
Offset Calibration
Inputs can be calibrated one at a time or all at once. To calibrate the offsets,
proceed as follows:
1. Apply power to the module for 20 minutes before calibrating.
2. Connect a precision millivolt source across each input channel. Set the
source to -320.00 mV for a gain of 1. Connect all (L) signal terminals
together and attach to the positive lead from the precision voltage
source. Connect all (-) signal terminals together and attach to the
negative lead.
1 1 gain = 2, input = 0.0 mV
1 2 gain = 4, input = -50 mV
1 3 gain = 8, input = -10.0 mV
1 4 gain = 16, input = -9 mV
1 5 gain = 32, input = 1.0 mV
Gain calibration all
channels
2 0 gain = 1, input = 320 mV
2 gain = 2, input = 320 mV
2 gain = 4, input = 110 mV
2 gain = 8, input = 70 mV
2 gain = 16, input = 29 mV
2 gain = 32, input = 19 mV
Config Word 3
EDT Command
bits 8…15 Meaning Config Word 3
bits 4…7 Config Word 3
bits 0…3 Meaning
EDT Commands for Offset Calibration
All Channels Single Channel
EDT Command
EDT
Command
Dec. or Hex
Bits 8
…
15
EDT Command
Data
Dec. or Hex
Gain
Selected Input (mV) Hex Decimal Bits
4
…
7
Bits
0
…
3
1 -320.00 + 0.064 mV 2410 9232 05
0 … 7
0
2 0.000 + 0.032 mV 2411 9233 05
0 … 7
1
4 -50.00 + 0.016 mV 2412 9234 05
0 … 7
2