Honeywell 05701-A-0301 System 57 Single Channel Control Card

Description

The Honeywell 05701-A-0301 is a microprocessor-based Single Channel Control Card within the System 57 engineering framework, developed to process, display, and manage field-mounted gas detection sensors. This control module interfaces seamlessly with 4 - 20mA gas transmitters or loop-powered gas sensors via an integrated plug-in sensor drive module. Operating as an independent element in high-integrity safety systems, the card performs constant validation of internal circuitry, active software operation, and physical sensor health.

The module translates complex electrochemical, toxic, or combustible field signals directly onto a dedicated four-part liquid crystal display on the front face, combining an analogue bar segment indicator with digital messaging readouts for localized engineering tracking. It evaluates live field inputs against programmable parameters to drive active alarm thresholds, coordinating safety loops across the backplane to drive relay behaviors and optional isolated multi-drop current monitors.

Features

• Built with a dedicated four-part liquid crystal display comprising a 25-segment analogue bar graph, a 4-character digital value window, a 4-character message line, and explicit operational icons.
• Equipped with low-latency front-panel status LEDs for A1, A2, A3 gas alarms, dedicated system Fault, and channel Inhibit indicators.
• Features an integrated, multi-functional front Reset/Select push-button to allow localized alarm clearing and card matching alongside a system Engineering Card.
• Provides high-granularity configuration with Alarm Setting Point Resolution fully adjustable in fine 1% fsd (full scale deflection) steps.
• Sustains precision safety monitoring using an electronic architecture boasting an exceptionally stable Electronic Drift pattern restricted to less than plus or minus 2% over a 6-month operational window.

Applications

• Multi-zone monitoring of toxic and flammable gases within industrial chemical processing plants, refineries, and offshore infrastructure platforms.
• Marshaling panel integration for processing inputs from loop-powered gas transmitters running into central instrumentation rooms.
• Specialized marine, utility, and heavy fabrication facilities requiring high-integrity independent gas detection channels.

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Sub-Rack Chamber Isolation: Install the module inside the designated, sealed electromagnetic interference (EMI) chamber of the 19-inch or half 19-inch System 57 sub-rack to safeguard precision logic components.
• Field Cabling Parameters: Attach all field connections via the dedicated mating Interface or Relay Card terminals, using multi-stranded shielded cables up to 2.5mm2 to secure input paths.
• Shield Grounding Methods: Terminate the external cable outer shield explicitly at the single Ground terminal block on the Interface/Relay Card or through standard metallic cable glands to isolate noise loop entry.
• Single-End Shield Policy: If field sensors are grounded locally through their structural enclosures or mounting plates, maintain the shielding continuity by connecting the screen sheath only at one termination point (either field end or rack end) to avert dangerous ground loops.
• Maximum Source Limits: Ensure that any connected loop-powered transmitter or auxiliary field instrument does not pull a continuous load exceeding 500mA from the individual display card pins.

FAQ

• How is the specific gas scaling and range profile configured on this module?

  Operational setups and range specifications are managed digitally via a microprocessor system and securely written to an onboard non-volatile EEPROM, which can be modified through an Engineering Card or linked interface PC running diagnostic software.

• Can this single channel card accept direct catalytic sensor bridge inputs?

  The 05701-A-0301 card is factory-equipped with a 4 - 20mA input conditioning module. For direct three-wire catalytic gas sensor installations, the sister card model 05701-A-0302 must be selected instead.

• What happens if a loop device requires more than the 500mA sourcing current limit?

  If a field transmitter demands an operational or start-up current value exceeding 500mA, it must be powered using an independent external 24V DC auxiliary field power supply loop rather than drawing directly from the card.

• Is it safe to pull the card out of the rack assembly while neighboring loops are running?

  Yes, each channel loop behaves as an independent circuit node, meaning separate control card cards can be unplugged or serviced inside a standard sub-rack arrangement without disrupting adjacent process security loops.