Ricos Rs 232/485; General Notes - Wieland ricos Manual

Basic principles, overview and ordering information

2.21.1 General notes

ricos RS 232/485 enables the connection of devices to the
The function module
ricos bus coupler with either a serial RS 232 interface or an RS 485 interface.
The RS 232 interface is suitable for data exchange between exactly two devices
while up to 32 devices can be linked using the RS 485 interface. Simultaneous
sending and receiving (full duplex operation) is possible with the RS 232 interface.
With the RS 232 interface, all the signals use the same earthing cable. The
extension of the transmission link is therefore limited to a few metres. The module
has been defined as data circuit-terminating equipment (DCE) by switching the
CTS signal as an output and the RTS signal as an input.
Establishing the connection: 1.)
X2.1 / RxD
ricos
RS 232
X2.0 / TxD
X2.2 / CTS
X2.3 / RTS
X2.4 / GND
Establishing the connection: 2.)
X2.5 / A
ricos
RS 485
X2.6/ B
X4.xx Schirm
Only a semi-duplex operation is possible due to the 2-core wiring (A/B) of the
RS485 interface. As is usual with the RS485 interface, both cable ends must be
terminated with a 120 ohm resistor. This resistor can be connected in the terminal
compartment of the spring-loaded terminals together with the signal cables (A/B).
The data that is transmitted by the
back and stored in the receiving buffer. Depending on the application, it is possible
to check whether the data has been sent correctly. For this reason, the receiving
buffer must also be deleted after sending, otherwise it can lead to an overflow in
the receiving buffer.
84
ricos RS 232/... <<<>>> PC
TxD / Pin 2
PC
etc.
RxD / Pin 3
CTS / Pin 7
RTS / Pin 8
GND / Pin 7
ricos .../485 <<<>>> RS 485 modem
A RS 485
Modem
B
ricos RS 485 module is simultaneously read
© 2002 Wieland Electric GmbH Version 2.4* (December 2002)
Part no. 05.591.3389.0 © 2002 Wieland Electric GmbH