Digital Motor Protection Relay (GDR-M02) User's Manual (V1.00)
30 / 76
KyongBo Electric Co.,Ltd
【
Figure 4.1
】
RS-232C Circuit
【
Figure 4.2
】
RS-232C Connect
Communication
Specification
Method
●
RS-232 / RS-485
Protocol
●
MODBUS
Communication
S t a n d a r d
( R S - 4 8 5 C )
Distance
●
1.2km
Line
●
Common RS-485C Two-Pair cable
Speed
●
300 ~ 19,200 bps
Method
●
Half-Duplex
Maximum
input-output
Voltage
●
-7V ~ +12V
Communication
P
o
r
t
Front Display
●
RS232 1port
●
300 ~ 19200 BPS, MODBUS Protocol
Back - Side
●
RS485 1port
●
300 ~ 19200 BPS, MODBUS Protocol
●
Upper SCADA Communication
●
Terminal number : 9(+), 11(-), 12(Com)
【
Table 4.2
】
Communication Method
4.2.2 RS-485C Communicaton
This relay provide isolated RS-485C Half Duplex communication method for linking
SCADA system. In this communication method can linked multi-drop and
communication distance is maximum 1.2km. RS-485C line end resistance is parallel
120
Ω
like
【
Figure 4.13
】
RS-485C Connection Diagram.