Foxboro P0916DC FBM2xx Series

The Foxboro P0916DC, also cataloged as the P0916DC Terminal Cable, operates as a dedicated hardware component for balancing digital communication lines within Foxboro I/A Series FBM2xx networks. It executes physical signal routing over a 3-meter fixed length to interface field transmitters to Fieldbus Modules, suppressing cross-talk in topologies utilizing a common external power supply.

Suffix Breakdown & Model Matrix

• P0916DC: Core Type 1 terminal cable assembly with an integrated Balun module designed for FBM2xx architectures requiring common-source digital communication line balancing.

Hardware Specifications

Channel-to-Channel Isolation & Balun Performance

The assembly incorporates a Balun module engineered to maintain line balance across 4-20 mA HART loop protocol paths when powered via an external power supply. This configuration isolates the common return path of multi-loop wiring, preventing the near-end cross-talk that occurs when field loops share common electrical points. The system enforces channel-to-channel isolation parameters up to the physical limitations of the 2500 Vrms optical isolation circuitry, preventing common-mode voltage spikes from disrupting backplane data packets.

Frequently Asked Questions

Q: Is the P0916DC cable required if the HART transmitters are powered directly from the internal FBM power source?

A: No. Loops utilizing the FBM internal power source maintain independent electrical isolation and do not experience the common-connection cross-talk caused by external power supplies. The line-balancing Balun function of the P0916DC is only active and necessary when field loops share a common external power supply line.

Q: Can the 3-meter physical length of this Type 1 cable be modified or spliced in the field?

A: No. Altering the physical length of the Type 1 cable modifies the impedance parameters calibrated for the Balun module. Splicing can introduce noise, alter signal attenuation, and degrade the 2500 Vrms optical isolation threshold.

Field Installation Guidelines

• Cable Management and Route Separation: Route the 3-meter cable assembly through dedicated low-voltage instrument trays. Maintain physical separation from high-voltage AC lines to prevent electromagnetic induction from bypassing the integrated Balun line-balancing sub-circuit.
• Bend Radius Restrictions: Do not exceed the minimum bend radius during installation inside the cabinet. Sharp bends can compromise the inner shield layering, which induces cross-talk at the system end of the loop wiring cable.
• Shield Grounding Discipline: Ensure the factory-installed shield drain wire is bound directly to the designated system reference ground terminal block. Avoid creating secondary ground paths, as multiple ground connections create loops that counteract the channel isolation features.
• Terminal Block Connection: Ensure all compression screw terminals are torqued to specific factory parameters to maintain a gas-tight, low-resistance interface across all 16 analog channels.