Adtech iMASTER – A1 Series User Manual page 35

A1-User's Manual
4) Sinking and Source Modes selection (Output signal)
RN0(RN2)
RN1(RN3)
5) Communication Connect
The termination resistor of the RS 485 2nd communication has a purpose of preventing the
distortion and attenuation of the communication line. This resistor means the impedance
matching resistor in long distance transport of RS 485 data. The termination resistor is inserted
only in the final stage in single line.
<Terminating resistance selection switch (SW1)>
Default Status: Terminating resistance ON
Regarding terminating resistance, only applied to RXP-RXN terminals
Turn off the switch when master communicate more than one of VFD
(For example master: PLC, DCS, PC and etc)
RS-485 Terminating resistance SW1 On:
RS-485 Terminating resistance SW1 Off:
COM
24V
VFD PLC
RXP
Transmit/Receive
+side
RN0(RN2)
RN1(RN3)
VFD
RXN
Transmit/Receive
-side
３１
COM
24V
PLC