Description
The Honeywell 05704‑A‑0145 is a four‑channel control card from Honeywell’s System 57/5704 series, designed to monitor and control up to four field gas‑detection channels using 4–20 mA (or 0–20 mA) signals. It plugs into a 3U 19‑inch sub‑rack and provides local indication, alarm processing, and analog outputs for integration with recorders, PLCs, or DCS systems.
Product description and key parameters
The 05704‑A‑0145 is a modular, rack‑mounted card used for industrial gas detection and monitoring:
- Channels
- 4 independent input channels per card.
- Supports standard 4–20 mA (loop‑powered) gas detectors and compatible 0–20 mA devices.
- Input characteristics
- Measurement range: typically 0–25 mA per channel (allowing headroom above 20 mA).
- Maximum loop resistance: up to about 500 Ω including sensor and field wiring.
- Power
- DC supply (fed via the rack): nominal 24 V, typical working range approximately 18–32 V DC.
- Power consumption typically under 10 W per card.
- Accuracy and performance (per channel)
- Alarm set‑point resolution generally 1% of full scale.
- Initial accuracy on the order of ±1% of full scale.
- Linearity around ±2% of full scale.
- Repeatability around ±2% of full scale.
- Physical
- 3U Eurocard‑style format, approx. 132 mm high, 25 mm wide, ~170 mm deep.
- Weight around 170 g.
- Front panel with display window, LEDs, and pushbuttons.
- Rear connectors (e.g. 26‑way and 32‑way types) for backplane and relay interface/field wiring, depending on rack configuration.
Each card can accept plug‑in analogue output modules on the front (one per channel) to provide individual 0–20 mA or 4–20 mA outputs for external systems.
HONEYWELL 05704-A-0145
Functional overview (datasheet‑style)
Functionally, the 05704‑A‑0145 acts as a four‑loop gas detection controller:
- Signal processing
- Reads each sensor’s 4–20 mA signal.
- Scales it to engineering units (e.g. %LEL, ppm) based on configuration.
- Displays channel readings and channel numbers on the front‑panel display.
- Alarm handling
- Multiple alarm levels per channel (commonly A1, A2, A3).
- Additional alarm concepts such as short‑term exposure limit (STEL) and long‑term exposure limit (LTEL) when configured for toxic gases.
- Alarm modes can be configured for master alarms, zoned alarms, or voted alarms using rack‑level logic.
- Front‑panel LEDs indicate alarm and status for each channel.
- Outputs
- Each channel can drive associated relay outputs (via a separate relay interface card in the rack) for alarms, shutdowns, or sirens.
- Optional analogue output modules provide isolated 0–20 mA or 4–20 mA output per channel for chart recorders, PLCs, or DCS.
- Remote functions
- Inputs for remote alarm reset and channel inhibit (disable) signals.
- Remote acknowledge and reset lines for system‑wide control, when used with engineering and alarm‑interface cards in the rack.
- Calibration and configuration
- Operated and configured using a dedicated engineering card installed in the same System 57 rack.
- Supports zero and span calibration for connected sensors.
- Engineering card allows setting alarm thresholds, testing relays, monitoring sensor currents, and setting rack clock/calendar.
The card self‑monitors its circuitry and sensor loop condition (open/short/fault) and can flag faults via LEDs and system alarms.
Origin
The 05704‑A‑0145 is a Honeywell industrial safety product, part of the System 57 / 5704F family originally developed under Honeywell’s fire and gas detection line. Design and manufacturing follow Honeywell’s industrial standards for fixed gas detection systems used worldwide in process industries and hazardous environments.
Recommended related Honeywell System 57 products (same brand)
If you use or specify the 05704‑A‑0145, the following Honeywell modules from the same family are commonly used together:
- 05701‑A‑0283 / 05701‑A‑0284 – Sensor Drive Modules
Plug‑in modules that condition the incoming sensor signals:- 05701‑A‑0283: 4–20 mA sensor drive module (for standard 4–20 mA transmitters).
- 05701‑A‑0284: Catalytic sensor drive module (for catalytic bead combustible‑gas sensors).
- 04200‑A‑0145 / 04200‑A‑0146 – Analogue Output Modules
Plug‑in analog output modules used with cards like 05704‑A‑0145 to provide isolated current loop outputs per channel:- 04200‑A‑0145: current sink type.
- 04200‑A‑0146: current source type.
- 05701‑A‑0361 – Engineering Card
Rack‑level card that manages backplane communication between control cards, provides system configuration and maintenance functions, and allows channel interrogation and calibration. - 05704‑A‑0144 – Four‑Channel Control Card (related variant)
Another four‑channel control card variant in the same mechanical family, selected depending on the exact application (e.g. fire vs gas, or specific sensor handling). - 05701‑A‑0326 / 0327 / 0328 / 0329 – Relay Cards
Various relay interface cards (field or sub‑rack mounted) that provide single, double, triple, or high‑integrity relay outputs driven by the control cards for alarm and shutdown functions.
These modules, combined in a 19‑inch System 57 rack with suitable power‑supply cards and cabinets, form a complete Honeywell fire and gas detection system, with 05704‑A‑0145 acting as a key multi‑channel gas detection and alarm control card.
