Rice Lake PR5230 Fieldbus Transmitter - Manual (Page 47)

PR 5230 Instrument Manual Installing the Instrument and Plug-in Cards
Sartorius EN-47
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
4-wire
2-wire
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 always 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