ST-72 User's Manual
Document: UM-1007
Revision Level A
54
!
!
SECTION 3
INPUT/OUTPUT BOARDS
3.1
MAIN I/O INTERFACE BOARD # 10-0331
The most basic ST-72 Controller requires only the I/O Board shown in Figure 3-1 for
interfacing to field wiring. The ST-72 primary power supply is applied to terminals 1 &
3(+) and 5 & 7(-) of TB4. 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 2 & 4(+) and 6 & 8(-) on TB4 provide up to 500mA of fused output
power for powering remote devices such as lamps, transmitters etc.
This Board includes two RS-485 ports that can be independently configured either
master
or
slave
, one Ethernet port, five Standard SPDT 5A relays, consisting of one
dedicated HORN and FAULT relay plus 3 programmable alarm relays, and power supply
I/O terminals. The Ethernet port allows the unit to be a ModbusTCP
Master and Slave
and also provides access to the embedded webpage. The failsafe Fault circuit detects
firmware and CPU failures along with transmitter failures. JP1 allows the RS-485 ports
to be configured for 2 or 4 wire operation. A 40 pin ribbon cable connects the I/O Board
to the ST-72 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 position 1 at 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 two COM 1 jumpers connects screw
terminals 1 & 5 and terminals 3 & 7 at TB3. RS-485 terminating resistors R5 (COM 1)
and R11 (COM 2) are located on the MAIN I/O Board and installed by moving the
jumpers at JP2 to position 1. These resistors should not be installed if the port is not at
the end of the communication line.
TB1 of the Main I/O Board allows the ST-72 to be acknowledged remotely. A low signal
at this input will simulate an Alarm Reset event (
). The ‘+’ input of
TB1 is pulled up to +5V. An external circuit or relay can pull the ‘+’ input low (to the ‘-‘
input) to activate the Alarm Reset event. The wiring to the external circuitry should be
no longer than 10 feet.
An optional Auxiliary Standard Relay
piggyback
Board (part # 10-0332) may be added to
the I/O Board via ribbon cable J3. This option adds another five SPDT 5A relays that
mimic the five standard relays. Auxiliary Standard Relay contacts are available at TB1 on
the optional 10-0332 shown in Figure 3-1.
An optional RS-485 Isolated
piggyback
Board (part # 10-0368) may be added to the I/O
Board via ribbon cable J5. This option adds two additional isolated RS-485 ports for a
total of four. These two additional serial ports can also be configured for either Master
or Slave. Horizontal jumpers installed in position 1 at JP2 & JP3 (com port 3) and JP5 &
Summary of Contents for ST-72
Page 106: ...ST 72 User s Manual Document UM 1007 Revision Level A 100...
Page 108: ...ST 72 User s Manual Document UM 1007 Revision Level A 102 Figure 6 4...
Page 128: ...ST 72 User s Manual Document UM 1007 Revision Level A 122 8 5 3 COPY CHANNELS Figure 8 7...
Page 129: ...ST 72 User s Manual Document UM 1007 Revision Level A 123 8 5 4 PROGRAMMABLE RELAYS Figure 8 8...
