Foxboro P0922VW FBM218 HART Analog I/O Module

Foxboro FBM218 P0927VW HART Analog I/O Interface

Configured for analog signal acquisition and HART device control in Foxboro Evo and I/A Series platforms, the Foxboro FBM218 P0922VW (FBM218 HART Analog I/O Module) provides direct physical and electrical execution of process loops. The hardware converts 16 channels of 4-20 mA analog inputs via 12-bit A/D conversion and drives 8 channel-isolated HART outputs over redundant 2 Mbps HDLC fieldbus links.

Suffix Breakdown & Model Matrix

The module catalog code reflects specific hardware configuration and physical part number assignments:

• FBM218: Base hardware architecture designating a 16-input / 8-output analog I/O field bus module family.
• P0922VW: Specific manufacturing part number representing the primary module assembly with channel isolation and HART modem integration.

Hardware Specifications

HART Protocol & Channel Isolation Performance

The Foxboro FBM218 P0922VW integrates dedicated Frequency-Shift Keying (FSK) modems on each of its 8 output channels, facilitating simultaneous 4-20 mA current loop output and bidirectional digital HART command execution. Channel-to-channel and channel-to-bus galvanic isolation barriers withstand up to 600 VAC potential differences for one minute. This physical separation suppresses ground loop currents, insulates module processing logic from field transients, and maintains 4-20 mA HART loop protocol signal integrity across dense process control racks.

Frequently Asked Questions

Q: How does the FBM218 maintain output state continuity during a primary module fault in redundant configurations?

A: In dual-module redundant pairings, the secondary tracking module continuously monitors backplane HDLC bus state data and master module diagnostic heartbeats. Upon master module fault detection, control transfer occurs automatically without step changes or disruptions to the 4-20 mA loop outputs.

Q: Can non-HART analog transmitters connect directly to the 16 analog input channels?

A: Yes. The 16 analog input channels accept standard 4-20 mA current loops from conventional non-HART analog transmitters, converting signals through 12-bit A/D converters at +/-0.1% full-scale accuracy.

Q: What physical isolation rating protects the module against field-side voltage surges?

A: Every channel features galvanic isolation rated to withstand 600 VAC for one minute between channels, chassis ground, and internal module logic circuits.

Field Installation Guidelines

Strict adherence to grounding and installation practices preserves signal accuracy and isolation limits:

1. Slide the module onto the designated baseplate position until the backplane connector latches fully engage the connector pins.
2. Tighten panel retaining screws firmly to establish mechanical grounding contact with the baseplate chassis ground rail.
3. Keep field analog signal cabling segregated from high-voltage AC conductors inside cabinet wiring ducts to avoid inductive noise coupling.
4. Terminate signal cable shield drain wires at a single point on the cabinet master instrument ground bus bar to eliminate ground loop currents.
5. Verify that field loop power supply voltages and load resistances match specified channel operating ranges before energizing field loops.