You can connect an IOM 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 you connect the IOM to an FC bus, wire the bus terminal block plugs on the controller and the other controllers in a daisy-chain configuration using 3-wire twisted, shielded cable as shown in Figure 1. See Table 1 for more information.
Figure 1. FC bus terminal block wiring
When you connect the IOM to an SA bus, wire the bus terminal block plugs on the controller and other SA bus devices in a daisy-chain configuration using 4-wire twisted, shielded cable as shown in Figure 2. See Table 1 for more information.
Figure 2. SA bus terminal block wiring
Note: The SA PWR/SHLD terminal does not supply 15 VDC. The SA PWR/SHLD terminal is
isolated and you can use the terminal to connect (daisy chain) the 15 VDC power leads on
the SA bus (Figure 2) or
the cable shields on the FC bus (Figure 1). The SA bus
supervisor advanced application field equipment controller (FAC), field equipment
controller (FEC), or VAV modular assembly (VMA) supplies 15 VDC to devices on the SA bus
that require power.