Field Calibration
WBPEEUI240774A0 4 - 7
There are three types of inputs on the ASI module:
• Low level voltage range (-100 to +100 millivolt).
• High level voltage range (-10 V to +10 V).
• Three-wire resistance range (5 ohms to 500 ohms).
Each of the 16 inputs can be used as a high level, a low level,
or a three-wire RTD input.
The high level, low level, and three-wire RTD inputs can be
field calibrated with this procedure.
ABB Automation recommends checking the accuracy of the
channel within each of the specified ranges after calibrating
each channel.
Test Equipment Required
The devices required to perform the field calibration are:
• One powered module mounting unit slot per ASI module
(+5 V with power fail interrupt).
• One controller with I/O expander bus dipshunts.
• A controller interface device such as a Composer or Con-
ductor workstation.
• An NKAS01 cable and its termination device (NTAI06).
Each input type to be field calibrated requires ultra-stable,
known precision sources.
Low-Level Voltage
Source
• -100 to +100 millivolt range with an accuracy of "10 micro-
volts (or "0.005 percent of this range).
• DC output resistance of less than 2.0 ohms.
High-Level Voltage
Source
• -10 V to +10 V range with an accuracy of "1.0 millivolt (or
"0.005 percent of this range).
• DC output resistance of less than 5.0 ohms.
Resistance Source
• 5.0 ohms to 500 ohms range with an accuracy of "25 mil-
liohms (or "0.005 percent of specified range).
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