3.2 Installation Technique
The following sections contain information for wiring the individual interface
types.
3.2.1 Installation Technique- RS232 Interface
The RS232 or V24 interface is the standard interface for a point-to-point con-
nection between two communication devices. The RS232 interface hardly offers
freedom from interruption and is only designed for short line lengths (max. 15m).
Basically, a distinction must be made whether the serial RS232C interface is con-
nected potential-free or galvanically with the chassis of the devices. A connection
to the device chassis is only useful for the non-floating connected RS232C inter-
face. With the CIF, PKV or Gateway, this is the first serial interface that is
available fixed on the base circuit board.
The RS232C interface is designed for relatively short lengths (max. 15m) . It is
assumed that both devices are earthed to the same protective conductor potential.
If, despite this, equalizing currents over the chassis connection in the non-floating
model still occur, then they are limited by the built-in 100 Ohm resistance. If the
devices are situated further apart, than we recommend that the data are transmit-
ted over the distance with RS422 level. For connected devices, the signals are
then converted to RS232C level via an interface modem. In this way distances up
to 100 m can be bridged.
Interface modems are offered, among others by the Phoenix company, e.g. model
PSM-V24/V11-P.
Appendix
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