Terminal blocks and bus ports
See Figure 1 for terminal block and bus port
locations on the expansion module. Observe the
following guidelines when wiring an expansion
module.
Input terminal blocks
The IOM3723 has inputs only (no outputs). The
inputs are located on both the top and bottom
of the expansion module. See Table 2 for more
information about I/O terminal functions,
requirements, and ratings.
SA/FC bus terminal block
An IOM can be connected to an SA bus or an FC bus,
but not to both buses simultaneously. The SA/FC
bus terminal block is a removable, 4-terminal plug
that fits into a board-mounted jack.
When connecting the IOM to an FC bus, wire the
bus terminal block plugs on the expansion module,
and the other expansion modules in a daisy-chain
configuration using 3-wire twisted, shielded cable as
shown in the following figure.
Figure 4: FC bus terminal block wiring
When connecting the IOM to an SA bus, wire the bus
terminal block plugs on the expansion module and
other SA bus devices in a daisy-chain configuration
using 4-wire twisted, shielded cable as shown in
Figure 5: SA bus terminal block wiring
Note:
The SA PWR/SHLD terminal does not
supply 15 VDC. The SA PWR/SHLD terminal
is isolated and can be used to connect (daisy
chain) the 15 VDC power leads on the SA bus
(Figure 5), or the cable shields on the FC bus
(Figure 4). The SA bus supervisor supplies 15
VDC to devices on the SA bus requiring power.
Supply power terminal block
The 24 VAC supply power terminal block is a gray,
removable, 3-terminal plug that fits into a board-
mounted jack on the top right of the expansion
module.
Wire the 24 VAC supply power wires from the
transformer to the HOT and COM terminals on the
terminal plug as shown in Figure 6. The middle
terminal on the supply power terminal block is not
used.
IOM3723 Input/Output Module Installation Guide
5