Phoenix Contact 2313669, User Manual, Page: 15 / 68

Description of the SHDSL permanent line modem
104275_en_c00 PHOENIX CONTACT
1-9
1.6 Supported network structures
1.6.1 Point-to-point connection
Figure 1-5 Point-to-point connection
A point-to-point connection is a direct connection between two devices without an interme-
diate station.
Distances of over 20 km can be covered at low data rates and with good cable quality.
In principle, the following interfaces can be used for a point-to-point connection:
– RS-232, up to 230.4 kbps
– RS-422, up to 2000 kbps
– RS-485 W2, up to 2000 kbps
In mixed operation with an RS-232 device and an RS-422 or RS-485 device, hardware or
software handshake is not supported.
In the case of RS-422 and RS-485, there are no cables designed for hardware hand-
shake. This is therefore not supported.
There is no defined general software handshake for all three interfaces. This is therefore
not supported either.
You can implement a point-to-point connection in which full and half duplex interfaces are
used (e.g., RS-485 and RS-232/RS-422). In this case, however, the protocol must ensure
that all interfaces are operated in half duplex mode.
In an RS-422 configuration (point-to-point connection), all termination resistors are acti-
vated automatically via the software.
In an RS-485 W2 configuration, the termination resistor can be enabled and disabled via
the PSI-CONF configuration software.
Table 1-1 Information on the interfaces
Interface basics Connection to the SHDSL modem
(connector pin assignment)
RS-232 See "RS-232" on page 1-6 See "RS-232 interface" on page 2-10
RS-422 See "RS-422" on page 1-7 See "RS-485 W2/RS-422 interface"
on page 2-11
RS-485 W2 See "RS-485 W2" on page 1-8
S
HD
S
L
S
HD
S
L
RS 232
RS 422
RS 485
RS 232
RS 422
RS 485
S HD S L 4 Wire
S
HD
S
L
S
HD
S
L
RS 232
RS 422
RS 485
RS 232
RS 422
RS 485
S HD S L 2 Wire