Technical Specifications
methods for connecting RTD module to the sensor. Among that, the RTD 4-Wire has the best
accuracy while the RTD 2-Wire has the lowest, therefore it’s recommended to only using RTD
2-Wire in application which not emphasis accuracy.
【RTD module Configuration】
SM231 module allows CTH200 series PLC to connect with multiple thermal resistance sensor.
Use DIP switches to select RTD type, wiring method, temperature scale and burnout direction.
The DIP switches are located on the bottom of the module as shown in Figure bellow. For the
DIP switch settings to take effect, you need to power cycle the PLC and/or the user 24V power
supply.
Table 4-5-5 SM231 RTD DIP switch configuration