Honeywell 07191/1/1 RS485 Communication Board

Honeywell 07191/1/1 RS485 Communication Board

Configured for serial data transmission in Honeywell automation network architectures, the Honeywell 07191/1/1 (07191/1/1 RS485 Communication Board) provides direct physical/electrical execution. It handles differential voltage signalling, half-duplex bus communication, and noise rejection protocols required for point-to-point and multi-drop field device interfaces without relaying network transmission overhead to the host processor.

Hardware Specifications

Channel-to-Channel Isolation & Loop Stability

The Honeywell 07191/1/1 integrates channel-to-channel isolation topology to prevent ground loop currents from degrading RS485 differential signals across long cable runs. Integrated line filter network and channel-to-channel isolation circuits stabilize serial frames against electromagnetic interference present in heavy industrial environments. By decoupling local system ground from external field cabling, the board maintains signal integrity and protects internal logic components against high common-mode voltage transients.

Frequently Asked Questions

Q: What grounding practice is recommended for the RS485 signal cable shield connected to the board?

A: The cable shield must be grounded at a single point, typically at the main controller ground bus, to avoid ground loop current loops. The shield drain wire at the module connection must remain isolated from high-voltage conduit grounds.

Q: Can the 07191/1/1 board be inserted or removed while the host rack is powered?

A: Power off the subsystem rack before inserting or removing the 07191/1/1 board unless the underlying Honeywell enclosure backplane explicitly supports hot-swap procedures for communication interface cards.

Field Installation Guidelines

1. Power down the rack chassis and verify zero potential across the backplane power terminals before inserting the board.
2. Align the printed circuit board edges with the card guides of the assigned enclosure slot and push firmly until the backplane connector seats completely.
3. Tighten all front panel retaining screws to secure mechanical grounding and prevent vibration-induced disconnects.
4. Route twisted-pair RS485 field wiring away from high-voltage AC lines, motor leads, and variable frequency drive output cables.
5. Install 120 ohm bus termination resistors across the differential signal lines at the two physical ends of the RS485 network segment.