Zero/Span Adjustment - Omron SYSMAC CJ1W-AD04U Operation Manual

Detailed Description of User Settings Area Data
4-2-3

Zero/Span Adjustment

1,2,3...
34
The zero point and span point can be adjusted for a process value.
The zero adjustment offsets the line plotting values before and after adjust-
ment parallel to the original line. The span adjustment changes the slope of
the line (i.e., the gain) around the minimum value in the range.
The zero adjustment value and the span adjustment gain are set in the DM
Area words allocated in the CPU Unit. The settings are applied to the value
after scaling.
These settings are refreshed during operation, so the values can be adjusted
under normal operating conditions.
Output data
Maximum range
Before adjustment
Minimum range
Zero adjustment value
The Universal Input Units zero/span can be adjusted using a calibration
device, as described below.
1. Connect the Programming Device to the CPU Unit.
2. The following table shows the appropriate calibration device to connect for
each input type.
Input type
Thermocouple input
Platinum resistance thermometer input
Voltage input
Current input
3. Turn ON the power to the PLC and calibration device, and wait for the re-
quired warm-up time.
4. Input a signal equivalent to 0% from the calibration device, and check the
process value in the CPU Unit's CIO Area using the Programming Device.
Zero/Span Adjustment
Thermocouple calibrator
Variable resistor
Voltage and current generator
Voltage and current generator
Section 4-2
Maximum range
Gain for
span
adjustment
After adjustment
Minimum range
Input
Calibration device