Honeywell NIAGARA WEB-700 - Manual (Page 14)

WEB-700 WEB-700-O CP-700
95-7776—03 14
SERIAL
There are two “RS” serial ports on the WEB/CP-700 base board. Each has a UART capable of operation up to 115,200 baud. At
the bottom of the board (see Fig. 6, page 13) is an RS-232 port using an DB-9 plug (male) connector. On the right side of the unit
is an isolated RS-485 port, using the bottom three terminals of a 6-position screw-terminal connector plug.
NOTE: Additional serial ports may be added with option card(s) in Option Slot 1 and Slot 2, such as an NPB-RS232
card, or NPB-2X-RS485 card (note the last option actually adds two serial ports).
RS-232
An RS-232 serial port using a male DB-9 connector always operates as COM1. You can use standard DB-9 serial cables with this
port. The WEB/CP-700 is a serial DTE device, another DTE device (PC, for example) requires a “null modem” cable. If
connecting to a DCE device (modem, for example), use a straight-through cable. Table 4. provides standard serial DB-9 pinouts.
NOTE: If rebooted with the mode jumper in the “Serial Shell” position (see Fig. 5, page 10), the RS-232 port provides
“system shell” access. See the NiagaraAX Install and Startup Guide for related details.
.
RS-485
An RS-485, optically isolated port is available on 3 pins of the 6-position right-side connector, and always operates as COM2. As
shown in Table 4, the screw terminals are minus (–), plus (+), and shield. Wire in a continuous multidrop fashion to other RS-485
devices, meaning “minus to minus”, “plus to plus,” and “shield to shield.” Connect the shield to earth ground at one end only, such
as at the WEB/CP-700.
Grounding
An earth ground spade lug (0.187") is provided on the controller for connection to earth ground. For maximum protection from
electrostatic discharge or other forms of EMI, connect the supplied earth grounding wire to this lug and a nearby earth ground.
Keep this wire as short as possible, see Fig. 7.
Table 4. Serial port (RS-232 and RS-485) pinouts.
Base RS-232 DB-9 Port (COM1) Base RS-485 Port (COM2)
Pinout Reference Signal DB-9 Pin Pinouts
DB-9 Plug
(male)
DCD Data carrier detect 1 6-Position end connector
(male)
RXD Receive data 2
TXD Transmit data 3
DTR Data terminal ready 4
GND Ground 5
DSR Data set ready 6
RTS Request to send 7
CTS Clear to send 8
not used on the 7 9
PS – (GND)
PS + (15V)
BB (12V Batt)
–
+
S
RS-485
Power