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 (FAC, FEC, or
VMA) supplies 15 VDC to devices on the SA bus
requiring power.
SA/FC bus port
The SA/FC bus port on the front of the expansion
module is an RJ-12, 6-position modular jack that
provides a connection for devices on the SA bus, a
Bluetooth
®
Commissioning Converter, or ZFR/ZFR
Pro Wireless Router (depending on which bus the
expansion module is operating on).
The SA/FC bus port is connected internally to the
SA/FC bus terminal block. See for more information.
The SA/FC bus port pin assignment is shown in
Figure 6: Pin number assignments for sensor, SA
bus and FC bus ports on expansion modules
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 the following figure. The
middle terminal on the supply power terminal block
is not used.
Figure 7: 24 VAC supply power terminal block
wiring
Note:
The supply power wire colors may
be different on transformers from other
manufacturers. Refer to the transformer
manufacturer’s instructions and the project
installation drawings for wiring details.
IOM3731-0A Expansion Input/Output Installation Guide
5