Current Loop Communication Expansion Kit
(For LE-3500XR/2500XR/



This expansion set supports the measurement of current loop communication which is still used in FA as a communication method resistant to external noise.

Applicable analyzers: LE-3500XR, LE-2500XR, LE-3500R, LE-2500R, LE-1500R, LE-3500, LE-2500, LE-1500


● Online monitoring of commonly used 10mA to 40mA current loop
● High-speed monitoring of current loop communication is available
● Passive and active simulation transmission output
● Current (20mA/40mA) at the active setting can be selected by DIP switch
● Signal polarity (current presence/absence) setting during non-communication corresponding to a line in which multiple nodes are connected by current loop
● Easy connection with the terminal block

Current loop measurement pod (adapter for current loop)

<Description of the dip switch>

Switch No.   OFF ON
1*1 SD side Passive Active
2*2 20mA supply 40mA supply
3*1 RD side Passive Active
4*2 20mA supply 40mA supply
*1: Set OFF for monitoring.
*2: The value of current loop is avaiable, only when "Active" is selected.

<Image of internal circuit (when set to passive type)>

<Internal circuit image (when set to active type)>

*: When monitoring, the transistor is always on.

Image of connection with current loop device to be testes

<Connection for monitoring>

<Connection for simulation (when working as active)>

<Connection for simulation (when working as passive)>

<Connection for simulation (when working as passive using an external DC power source)>