Description
Honeywell 51303979-100H
Technical Specifications
- Host Interface: DCS rack proprietary backplane bus
- External Serial Port: RS232 / RS485 configurable hardware interface
- Communication Protocol: Honeywell proprietary serial protocol, compatible with selected Modbus variants
- Isolation: 500 VAC isolation between rack logic side and serial field side
- Operating Temperature: 0 °C to +60 °C
- Power Supply: 5 VDC and 24 VDC from rack backplane
- Form Factor: Plug-in rack card
Functional Features Bidirectional protocol translation between internal DCS bus and external serial bus. Frame checksum verification for all inbound and outbound serial messages. Serial bus fault detection including cable break, no response and parity error. Front panel TX, RX and fault LED indicators. Message buffer prevents data loss during burst transmission. Communication fault timestamp upload to DCS event log.
Application Scenarios DCS connection to online gas and liquid process analyzers Remote serial RTU data integration into legacy Honeywell DCS Process data transmission to external chart recorder and historian equipment Legacy serial communication spare replacement
Performance Parameters
- Serial baud rate range: 300 bps up to 19200 bps configurable
- Message forwarding latency: Deterministic within DCS scan cycle
- Fault detection response: <200 ms
- Isolation withstand voltage: 500 VAC for 60 seconds
Material Composition FR4 multilayer PCB, serial transceiver IC, protocol processing FPGA, optocoupler isolation components, TVS surge suppression diodes, screw terminal block for RS485 wiring, DB9 connector for RS232, flame retardant plastic housing, gold plated backplane edge connector.
Structural Features Standard plug-in rack card form factor. Front panel LED indicators for transmit, receive and fault state. External serial connectors arranged on front panel for field wiring access. Internal isolation barrier separates rack logic circuit and external serial circuit. Anti-keying notch prevents reversed insertion.
Working Principle DCS controller sends read or write request over rack backplane bus. Onboard FPGA repackages request into serial protocol frame and transmits to external device. Response frame received from serial port is validated by checksum, parsed and converted back to DCS bus message format before sending to controller. Continuous bus monitoring detects timeout and framing error.
Installation Requirements RS485 field wiring uses twisted pair differential cable and install termination resistor at bus far end. Separate serial communication cable from high voltage power wiring. Configure baud rate, parity and protocol mode to match connected third-party device. Tighten terminal screws to specified torque value.
Usage Notes Do not swap A and B differential lines on RS485 bus. Duplicate termination resistors cause communication failure. External surge protection is required for long distance field serial cable runs. Do not modify onboard protocol firmware without factory release package.
