Electrical connection
CUM 750 / CUS 70
14
Hauser
4.3.3 Connecting the analogue output and serial ports
The measuring system is designed for up to four 4-20mA analogue outputs, one per sensor.
The connection uses a 14-pin PHOENIX plug-connector, which also contains the pins for the RS 485
and RS 232 serial ports.
Connecting the X2 terminal block
Pin No.
Name
Description
1
+ (1)
2
- (1)
Analogue output 1, 4-20mA
3
+ (2)
4
- (2)
Analogue output 2, 4-20mA
5
+ (3)
6
- (3)
Analogue output 3, 4-20mA
7
+ (4)
8
- (4)
Analogue output 4, 4-20mA
9
RS 232 RX
RS 232 Received data
10
RS 232 TX
RS 232 Sent data
11
RS 232 GND
RS 232 Earth (not screened)
12
RS 485 +
RS 485 Positive
13
RS 485 S
RS 485 Screen
14
RS 485 -
RS 485 Negative
RS 485 serial port
In applications where an RS 485 interface is available, several systems can be connected in the
multidrop mode of the RS 485.
Note:
•
The RS 485 serial port has a galvanic separation voltage of 1600Vrms/min or 2000Vrms/s.
•
The RS 484 serial port has transient protection through very fast voltage limiter. PTC thermistors
ensure constant protection against overvoltages.
RS 232 serial port
The RS 232 serial port is intended for applications where there are only short connections
between the transmitter and the user terminal.
Caution!
•
The RS 232 serial port has neither galvanic separation nor transient protection. Do not use the RS
232 in environments where large voltage transients are possible. To avoid this, route the RS 232
cable with an earthed screen.
