Oldham WX16, User Manual

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WX16 User Manual | 27
SECTION 3
3.0 Main I/O Interface PCB #10-0142
The most basic WX16 Controller requires only the I/O PCB shown in Figure
3.1 for interfacing to field wiring. The WX16 primary power supply is applied
to terminals 9 & 11 of TB2. This may be from 10 – 30 VDC.
WARNING !
HIGH VOLTAGES SUCH AS 115 VAC APPLIED TO THESE TERMINALS
MAY CAUSE SEVERE DAMAGE!
DC output terminals 10 & 12 on TB2
provide up to 500mA of output power for powering remote devices such as
lamps, transmitters, etc.
This PCB includes both master (COMM 1) and slave (COMM 2) RS-485 ModBus
ports, 5 amp form C relays for each common alarm event (A1, A2, FAULT/A3 &
HORN), and power supply I/O terminals. JP1 allows the RS-485 ports to be configured
for 2- or 4-wire operation. A 26-pin ribbon cable connects the I/O PCB to the WX16
CPU and Display nest assembly. Two I
2
C bus connectors allow addition of optional
functions such as analog I/O and discrete alarm relays for each channel.
Horizontal jumpers installed in JP1 connect the RS-485 port’s RX & TX lines,
simplifying 2-wire daisy chains by providing additional terminals for incoming and
outgoing cables. For example, installing the 2 COM 1 jumpers connects screw
terminals 1 & 5 and terminals 3 & 7. Socketed RS-485 terminating resistors R6
(COMM 1) and R12 (COMM 2) are located on the MAIN I/O board. These resistors
should be removed if communication wire lengths are very short (less than 25 feet) or if
the port is not at the end of the communication line.
An optional Auxiliary Relays piggyback PCB (part #10-0144) may be added to the I/O
PCB via ribbon cable J4. These add another form C contact set to the common A1, A2
and HORN alarms. Auxiliary Relay contacts are available at the TB1 (AUX) terminals
shown in Figure 3.1.