FC 73 - Calibration (NAMM02 - IMAMM03)

The calibration function block contains the offset and gain error correction factors determined during I/O module or point calibration. Function code 74 performs the I/O module calibration. Fixed numbers equal to the input block (one through 64) number plus 100 (blocks 101 through 164) reference the calibration data function block. The output is the raw value of the input in millivolts, corrected for use by the NAMM02/ IMAMM03 Analog Master Module.

 

 

Outputs:

Blk

Type

Description

N

R

Raw value of the input in mV, corrected for use by the NAMM02/ IMAMM03

 

 

Specifications:

Spec

Tune

Default

Type

Range

Description

S1

N

-0.500

R

Full

Offset error correction factor

S2

Y

-0.500

R

Full

Gain error factor

 

 

73.1  Explanation

 

The calibration block can provide a test of the point or I/O

module operation.

 

1. Monitor the block input of the I/O module (one to 64 + 100). This value is the raw millivolt output.

2. Record the offset error correction (S1) and gain error (S2) factor of the same block in Step 1.

3. Calculate the temperature as follows:

 

(raw - offset) X gain = corrected millivolts

 

where:

 

raw = Value of input block number

(one through 64) plus 100 (101 through 164)

 

offset = Offset error correction factor (value of S1)

 

gain = Gain error factor (value of S2)

 

NOTE: An increase in offset decreases the temperature and a

decrease in offset increases the temperature.