Example - Johnson Controls - LIT-12012523 - Temperature Data Acquisition (TDA) Module

Temperature Data Acquisition (TDA) Module Technical Bulletin

Brand
Johnson Controls
Product name
Temperature Data Acquisition (TDA) Module
Document type
Installation Instructions
Document number
LIT-12012523
Revision date
2021-03-30
Language
English

CWR1 (Input 2) requires a single point field calibration. A 10,000 ohms ±100ppm reference resistor is connected to the input through the field wiring.

Table 1. Single Point Calibration Example

Step

Action

Recorded Result

Connect reference resistance to the input of the TE-74, record reference resistance value.

Record Reference Resistance

10,000.0 ohms

Allow input to settle, record present value of the input resistance.

Record present value of CWR1-R

10,004.5 ohms

Subtract the recorded present value from the reference resistance value, command field Zero Reference to the difference.

Command CWR1-Zero Reference to difference of CWR1-R present value and reference resistance

10,000 ohms - 10004.5 ohms = -4.5 ohms