User manual

Publication 1797-6.5.1 - April 1999
5-2 Calibrating Your Module
Use one of the following general methods to calibrate your module:
• Use intrinsically safe equipment to calibrate the module.
• Use factory trained personnel under controlled conditions to calibrate the
modules with non-intrinsically safe equipment to maintain your
module’s intrinsic safety certification.
Tools and Equipment
To calibrate your analog I/O modules, you will need the following tools and
equipment:
Using Calibration Module
Command Words
Module calibration is supported by Module Command words. See your
module data tables in Chapter 3 to determine which words are the Module
Command words. They are always the last read word and last write word.
The Module Command word is broken into two parts the upper byte is the
command and the lower byte is the data.
A CIO is used to structure a calibration command and submit it to the
network. This includes the command and any data.
MODULE Command Word

ATTENTION: With the second method, extreme care must be
exercised by the calibration personnel to avoid compromising
the intrinsically safe characteristics or your modules. This
method may never be used in a hazardous environment.
Tool or Equipment: Description:
Precision Current
Source
0-22mA, 0.01µA resolution Used for 1797-IE8 module
Precision Current Meter 0-22mA, 0.01µA resolution Used for 1797-OE8 module
Industrial Terminal and
Interconnect Cable
Programming terminal for A-B family processors
R/W Bit
1514131211109876543210
Write cmd
flag
MODULE calibration command MODULE calibration command data