LG GLOFA-GM Series User Manual page 42

Chapter 4 Performance specification
[Figure 4.9] RS-485 connection
Computer link side
Pin No. Name
1 RDA(RXA)
2 RDB(RXB)
3 SDA(TXA)
4 SDB(TXB)
5 S.G(SG)
6
[Figure4.9] shows how to connect RS-485 multi-drop communication. In case of multi-drop communication, to
connect with external devices, RDA and SDA, RDB and SDB of RS-422 channel shall be connected each other. At
this time half-duplex communication is run sharing Tx/Rx line, so RS-422 channel mode shall be applied as set to RS-
485 in Frame Editor.
Remark
[Note1] G7L-CUEC does not use Frame Editor and is designed to be set automatically by communication
parameter of GMWIN.
(Cnet<--->external devices)
F.G
Signal direction
4-10
External communication
device
SDA
SDB
RDA
RDB
S.G
F.G