Technical Manual
PD4-N5918
Connections and circuits
18
Issue: V 1.4
Notes on the baud rate
It is important to note that both the controller and the CAN master use the same baud
rate. Only this way can communication be established.
The baud rate has a direct influence on the maximum possible bus length. The
following list shows the possible baud rates as well as their maximum permissible bus
lengths:
Baud rate Bus length
1 MBaud 40 m
500 kBaud 130 m
250 kBaud 270 m
125 kBaud 530 m
50 kBaud 1300 m
20 kBaud 3300 m
Notes on the bus termination
With CAN, the bus termination is handled by two 120 ohm resistors on both ends of
the bus.
Two-wire operation RS485
To enable RS485 two-wire transmission capability, all bus stations must have a
direction control.
An intelligent converter, which automatically switches to transmission mode when a
start bit is received at the RS232 interface and returns to reception mode at the end of
the stop bit, enables two-wire operation of the PD4-N. This solution requires no
software support.
We can recommend the ICP-7520 converter, for example, that is available from
Schuricht.
Talk to our Technical Hotline if you require support for this.
