Siemens SIMATIC TIWAY 1 User Manual page 79

THE TIWAY I NETWORK PORTS
4.1.2 Modem Interface
Port Port Port Port AC AC
GND
1 2 3 4 NEUT LINE
I/O
1 2 3 4 5
Interface Ports
A000654
Figure 4–4 RS–232–C/RS–423–A Modem Interface Ports
The modem interface is a standard "Type E" DTE configuration as defined in the
EIA RS–232–C standard that uses EIA RS–423–A drivers. This interface uses a
female 25-pin "D" type connector on both Ports 1 and 2 as shown in Figure 4–4.
These two ports support redundant media transmission when connected to
redundant modem networks. The pin assignments shown in Table 4–3 are
supported. All other pins should be left vacant to prevent damage which may be
caused by non-standard pin usage.
4–5 UNILINK HOST ADAPTER
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