Foxboro FBM2/36 P0500RG Termination Cable Assembly

The Foxboro FBM2/36 P0500RG, also cataloged as the P0500RG Termination Cable Assembly, operates as a dedicated hardware component for field transmitter interfacing within I/A Series DCS networks. Configured for multi-channel data paths linked to active FBM2 and FBM36 base units, this structural cable system provides direct point-to-point electrical route management between cabinet field terminals and input/output cards. The assembly drives analog or mixed instrumentation signals directly to the subsystem backplane architecture without active processing overhead or latency.

Hardware Specifications

Channel-to-Channel Isolation & Signal Preservation

The physical internal wiring of the P0500RG assembly is optimized to safeguard the 4-20 mA HART loop protocol against high-frequency electromagnetic distortion. Individual conductors use twisted-pair symmetry inside a collective EMI/RFI shielded metallic envelope to prevent parallel line capacitance from degrading digital frequency-shift keying (FSK) superimpositions. This layout delivers structural channel-to-channel isolation that stops parasitic ground currents from altering parallel circuit baselines. For temperature sensor routing, the high-conductivity copper traces minimize localized thermal gradients, securing the line path symmetry required for precise cold junction compensation (CJC) processing at the active FBM interface.

Frequently Asked Questions

Q: Does the physical connection or extraction of the P0500RG interrupt neighboring FBM modules?

A: No. The passive multi-channel interface is structurally separated per module slot. Live mechanical connection or hot-plug removal of the cable does not cause bus impedance drops or signal interruptions on adjacent active backplane slots.

Q: What is the continuous dielectric breakdown limit of this termination cable assembly?

A: The insulation parameters are rated to withstand operational potentials up to 250 VAC / 400 VDC with a minimum insulation resistance baseline of 1000 M-Ohm. Exceeding these limits will cause dielectric degradation and localized channel short circuits.

Q: How is wire fault diagnostics handled across this passive cable path?

A: The P0500RG contains no active digital logic or microprocessors. Loop diagnostic anomalies, including open-circuits or short-circuits, are detected exclusively by the measurement circuitry of the paired active FBM2 or FBM36 module.

Field Installation Guidelines

• Bend Radius and Routing Constraints: Install the termination cable through dedicated low-voltage wire trays inside the enclosure. Maintain a physical bend radius of no less than 10 times the outside cable diameter to prevent mechanical stress or fracturing of the internal copper conductors and shield layers.
• Shield Grounding Matrix: Terminate the collective EMI/RFI shield braid at a single point on the central instrument earth ground bar within the control cabinet. Do not ground the shield at both the field junction box and the termination frame to eliminate circulating ground loop paths.
• Parallel Cable Segregation: Separate the low-voltage analog signal cables from high-power AC lines, inductive motor circuits, and switched relay bundles. Maintain a minimum physical distance of 300 mm to suppress capacitive cross-talk and induction noise.
• Mechanical Strain Relief: Ensure both ends of the 140 cm assembly are physically anchored using the integrated mechanical strain reliefs. Field conductors joined to screw or solder points must be stripped to 7 mm and secured to standard torque limits to ensure point-contact electrical stability.