Central Processing Unit
5–20
1070 072 145-102 (01.07) GB
Transmission protocol
The following transmission protocol is permanently set:
D Even parity
D 1 Stop bit
D 8 Data bits
There are no control lines.
V.24 interface
As the V.24 interface is not electrically isolated from logic circuits and power
supply, this may on rare occasions connectivity problems with devices
whose interface also lacks electrical isolation.
If this is the case, sufficient potential equalization must be established bet-
ween the reference conductors of both interfaces. Only a small potential dif-
ferential may exist between transmitter and receiver, for example:
–2 V < U
diff
< +2 V.
Signal level: logic 1 –5 V
logic 0 +5 V
Pin assignment, female DB-25 connector:
Pin Signal designation Signal function
Housing Screen Screening
2 TxD PLC transmit data
3 RxD PLC receive data
7 GND Reference conductor, Ground
20 mA interface
Line status: logic 1 : 20 mA
logic 0 : no current
Pin assignment, female DB-25 connector (passive):
Pin Signal designation Signal function
Housing Screen Screening
21 12 V GND 12 V reference conductor
22 RXD+ Receive data +
12 RXD– Receive data –
23 TXD+ Transmit data +
13 TXD– Transmit data –
To Next Page
Loading...
