Vishay G4 - CPU Unit Communication Interfaces; COM1 RS-232 Communication; COM2 RS-485 Communication

G4 Multi Channel Weighing Instrument
CPU unit
External computing devices connected to the CPU communication interfaces
of the instrument have to comply with the standard, UL 60950.
The internal battery in the CPU module is to be used only in the equipment
where servicing of the battery circuit and replacement of the lithium battery
!
will be done by a trained technician.
COM1
RS-232 Serial communication.
This is a SELV/SELV-E circuit.
COM1 can be used for serial communication
with computer/PLC (Modbus RTU) or a
printer.
Point to point communication, only one
G4 unit connected to the computer/PLC.
Connections are made to terminals
7 to 9. Shielded cable must be used.
Connect the shield to terminal 10.
COM2
RS-485 Serial communication for
2-wire or 4-wire with common 0 V.
This is a SELV/SELV-E circuit.
Communication port COM2 can be
used for serial communication with
computer/PLC (Modbus RTU) or a
printer.
Connections are made to terminals
1 to 5. Shielded cable must be used.
Connect the shield to terminal 6.
The communication lines must be
terminated at both ends.
If G4 is connected at the end of
the communication line, the switches
T2 and R2 must be set according to
the table below.
2-wire termination:
Both T2 switches ON,
both R2 switches OFF.
4-wire termination:
Both T2 switches ON
both R2 switches ON.
(DTE)
RS-232
9p 25p
2 3
3 2
5 7
TX
RX
0V
Shield
COM1 RS-232
10
9
8
7
RS485 2-wire
COM2
+5
0
+5
0
+5
0
R2
+5
R2
0
1
T-
T+
R-
R+
0 V
Shield
6
2
3
4
5
T2
T2
R2
R2
RS485 4-wire
COM2
T2
T2
1
T-
T+
R-
R+
0 V
Shield
6
2
3
4
5
17