W-NXS AND CP-NXS
74-4059—01
18
RS-232
A standard RS-232 serial port uses a DB-9 male connector, and is labeled “COM” (see
on page 11). It
operates as COM1 in software. A standard “null-modem” cable can be used to communicate to another DTE device,
or a “straight-through” cable can be used to communicate to a DCE device, such as a modem.
Note
Use only
shielded cable
for any RS-232 connection, such as available with a standard (pre-fabricated)
straight-though or null-modem cable. If fabricating a cable, connect the shield (drain) wire to the DB-9S
(socket) connector shell at the JACE end only—do not connect the drain wire at the other end.
RS-485
An RS-485, optically isolated port uses a 3-position, screw terminal connector and always operates as COM2. Wire
to this connector with shielded 18-22AWG wiring (refer to the TIA/EIA-485 standard). As shown in
, the RS-
485 screw terminals (from left-to-right) are shield (GND), Data plus (+), and Data minus (–).
Figure 15
RS-485 port (COM2) pinouts
LonWorks
A single, two-pin, male LonWorks FTT-10A connector port and wiring plug is available (see
). This
connection supports twisted pair, unshielded, polarity-insensitive, peer-to-peer communications at 78 Kbps.
Refer to the
LonWorks FTT-10A Free Topology Transceiver User’s Guide
(078-0156-01F) for technical guidelines
associated with free topology restrictions, and the
Junction Box and Wiring Guidelines for Twisted Pair LonWorks
Networks
(005-0023-01) for more detailed information on wiring specifications. These documents are available on
Echelon’s web site (www.echelon.com).
RS-485 port
GND D
+
D
–
FTT-10A
LON
