Installing the Instrument and Plug-in Cards
PR5230 Instrument Manual
EN-46
Sartorius
4.2.9
Interface RS-485
The instrument is provided with a built-in RS-485/422 interface.
When mounting, the RS-485 interface must be configured by DIL switch S401 on the card.
Using RS-485 is compulsory with a multi-point connection (Tristate status). The RS-485 interface can be used
also for point-to-point connection.
Connection
5-pin plug-in terminal block
Number of channels
1 RS-485
Type
Full duplex
Transfer rate
300…19,200 bit/sec
Signals
TxA, RxA, TxB, RxB
Electrical isolation
Yes
Cable length
Max. 1000 m
Cable type
shielded twisted pair
(e.g. LifYCY 3x2x0.20),
1 pair of wires for GND
DIL switch S401
Block diagram RS-485
TxB
RxD/TxD-P
RxD/TxD-N
TxA
RxB
RxA
4
5
3
2
1
GND
S4
S1
S2
S6
S7
S3
1K6
1K6
120
120
S5
DC
DC
1 2 3 4 5 6 7 8
ON
DIP
S
Function
Settings for RS-485
1
Rx bus termination
OFF: not connected
ON: (RxA 120 ¥ RxB)
2
Rx pull-up resistor
OFF: not connected
ON: (RxB 1K6 ¥ +V)
3
Rx pull-down resistor
OFF: not connected
ON: (RxA 1K6 ¥ -V)
4
Tx/Rx bus termination
OFF: not connected
ON: (TxA 120 ¥ TxB)
5
Change-over 2- / 4-wire
OFF: 4-wire
ON: 2-wire
6
Rx enable
OFF: Rx disabled, if Tx enabled:
S7 must be ON.
ON: Rx immer enabled: For
4-wire S7 must be OFF.
7
Tx enable/Rx disable (2-wire)
OFF: S6 must be ON.
ON: S6 must be OFF.
8
n. c.
no function
