An XPM can be connected to a Sensor/Actuator (SA) bus or a Field Controller (FC) bus, but not to both buses simultaneously. The SA/FC bus terminal block is a removable, 4-pin terminal block that fits into a board-mounted pin header.
When connecting the XPM to an FC bus, wire the bus terminal blocks on the expansion module, and the other FC Bus devices in a daisy-chain configuration using 3-wire twisted, shielded cable as shown in the following figure. See Communications bus and supply power wiring guidelines for more information about communication bus terminal block functions, ratings and requirements.
When connecting the XPM to an SA bus, wire the bus terminal blocks on the expansion module and other SA bus devices in a daisy-chain configuration using 4-wire twisted, shielded cable as shown in the following figure. See Communications bus and supply power wiring guidelines for more information about communication bus terminal block functions, ratings and requirements.
The PWR/SHD terminal does not supply 15 VDC. The PWR/SHD terminal is isolated and can be used to connect (daisy chain) the 15 VDC power leads on the SA bus or the cable shields on the FC bus.
The SA bus supervisor (CGE, CGM, CVE, CVM, FAC, FEC, or VMA Controllers) supplies 15 VDC to the devices on the SA bus that require power.