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Set LT (termination resistance) switch

When a JW-20CM master module is at either end the communication line, make sure to set the termination resistance switch "ON."



Turn ON the termination resistance switches on these two stations.

Reference: Function of the termination resistance switch

If the communication line does not have a termination resistance, the high frequency signal will be reflected at the ends of the cable. These reflected signals can collide with the original communication signals, so that some stations will not be able to communicate normally. The use of termination resistance suppresses reflected signals. If the termination resistance switch on any of the stations in between the end of the cable is turned ON, the station will generate a reflection wave signal or attenuate the original signal and may not communicate normally.

· When the trunk line has a branch in it, turn ON the termination resistance at the station on the


trunk cable.














Drop cable






resistance (ON)




"T" branch


(branch line should

















be less than 400 mm)




























Trunk cable






·If you use a terminator (termination resistance made by Toko Denshi: ME-75) at the end of a signal cable, turn OFF the termination resistance at the station on the end of the cable.



Less than 1 km

Terminator: ME-75

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