Vishay G4, Техническое руководство, Страница: 21 / 200

G4 Multi Channel Weighing Instrument
2-3
!
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
RS232 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 - 9. Shielded cable must be used.
Connect shield to terminal 10.
COM2
RS485 Serial communication for 2-wire or 4-wire with common 0 V.
This is a SELV/SELV-E circuit.
COM2 can be used for serial communication to computer/PLC (Modbus
RTU) or a printer. Connections are made to terminals 1 - 5. Shielded
cable must be used. Connect shield to terminal 6.
The communication lines must be terminated in both ends. If G4 is
connected at the end of the communication line switches must be set
as:
2-wire termination: Both T2 ON, both R2 OFF.
4-wire termination: Both T2 ON, both R2 ON.
RS485 2-wire
1
T-
T+
R-
R+
0 V
Shield
COM2
6
2
3
4
5
+5
T2
T2
0
+5
R2
R2
0
RS485 4-wire
1
T-
T+
R-
R+
0 V
Shield
COM2
6
2
3
4
5
+5
R2
R2
0
+5
T2
T2
0
TX
RX
0V
Shield
COM1 RS-232
10
9
8
7
(DTE)
RS-232
9p 25p
2 3
3 2
5 7