LSIS XGB Series, User Manual, Page: 405 / 618

Chapter 11 RTD Input Option Board (XBO-RD01A)
11.8 Disconnection Detection Function
(1) As a module used to measure the temperature with the RTD temperature sensor directly
connected, it detects and displays disconnection of the sensor connected. If any disconnection
occurs in the sensor used and extended lead wire, it will turn on the disconnection diction bit
(2) The figure below shows the temperature sensor’s appearance of the 3-wired RTD.
(The appearance depends on sensor type)
* A disconnection: if disconnected between terminal A and module terminal block in the sensor
figure.
* B disconnection: if disconnected between terminal B (two for 3-wired sensor) and module
terminal block in the sensor figure, or if A and B lines are all disconnected.
(3) The basic connection between RTD module and RTD Sensor is based on 3-wired RTD sensor.
If 2-wired or 4-wired sensor is used, the connection between the sensor and the module shall be
kept as 3-wired. Disconnection will be detected on the basis of 3-wired wiring.
(4) In case of disconnection, operation of disconnection flag is as follows.
Connection status Channel status Disconnection flag
Normal
Run Off
Stop Off
Disconnection
Run On
Stop
Off
Any sensor is not
connected
Run
On
Stop Off
A terminal
B terminal
B
b
A
Module terminal block
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