Description
Honeywell 05701-A-0326 | System 57 Field Interface Card | Sensor Input Interface
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 05701-A-0326 |
| Manufacturer | Honeywell Analytics |
| System | System 57 |
| Control System | 5701 Control System |
| Product Type | Field Interface Card |
| Primary Function | Sensor-to-control-card field interface |
| Relay Outputs | None |
| Intended Channel | Non-master channels in systems with master relays |
| Sensor Connections | Sensor S, Sensor 01, Sensor NS |
| Analog Output Connections | Analog O/P + and – |
| Remote Inputs | Remote Inhibit, Remote Reset |
| Supply Connections | +24 V and 0 V |
| Mounting Architecture | System 57 card/rack assembly |
Honeywell’s System 57 manual specifically identifies 05701-A-0326 as the Field Interface Card. It is used in systems with master relays and on channels other than the master channel; its purpose is to provide the connection between the sensor and the control card, with no relays installed on this card.
The documented rear/front access connections include sensor connections, analog output terminals, remote inhibit/reset inputs, and +24 V/0 V connections.
Product Introduction
What the Honeywell 05701-A-0326 Does
The Honeywell 05701-A-0326 is a field interface card for the System 57 5701 gas detection control system. It sits between the field sensor wiring and the corresponding single-channel control card, providing the required electrical termination and signal path without adding alarm relays.
This distinction matters when sourcing a replacement. The card is not the gas sensor, single-channel alarm/control card, or a conventional PLC analog input module. Honeywell’s current accessory listing also identifies 05701-A-0326 as “SYS57 RELAY CARD FIELD INTERFACE.”
05701-A-0326
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
Legacy gas detection panels often remain in service long after their original control architecture has become difficult to source. A field interface card may look electrically simple, but its terminal arrangement and relationship with the control card determine whether the replacement actually fits the installed System 57 channel.
Typical Applications
- System 57 gas detection panels — field termination between gas sensors and single-channel control cards.
- Non-master detection channels — installations using a separate master relay arrangement.
- Legacy plant gas monitoring — replacement of damaged or failed interface cards without changing the complete detection panel.
- Maintenance stock — spare-card inventory for operating System 57 installations.
Technical Pitfalls to Avoid
- Do not treat 05701-A-0326 as an analog I/O module.
Several online listings incorrectly assign generic analog-input/output specifications to this part. Honeywell’s System 57 documentation identifies it specifically as a field interface card. - Do not substitute a relay card simply because the connector arrangement looks similar.
The 05701-A-0326 has no relays. The 05701-A-0327 and 05701-A-0328 are different cards that add relay functions. - Check the channel architecture before installation.
The 05701-A-0326 is intended for channels other than the master in systems using master relays. Confirm the panel configuration and associated single-channel control card before replacing it.
Related Products
- Honeywell 05701-A-0301 — System 57 single-channel control card for 4–20 mA input.
- Honeywell 05701-A-0302 — System 57 single-channel control card for catalytic direct-sensor input.
- Honeywell 05701-A-0325 — System 57 DC input card.
- Honeywell 05701-A-0327 — Double SPCO relay card; provides the field interface plus relay contacts for alarm/fault functions.
- Honeywell 05701-A-0328 — Triple SPCO relay card; adds relay contacts for A1, A2, A3, fault, and inhibit functions.
- Honeywell 05701-A-0351 — System 57 single-channel control card.
- Honeywell 05701-A-0283 — System 57 4–20 mA sensor drive module.
- Honeywell 05701-A-0284 — System 57 catalytic sensor drive module.
- Honeywell 05701-A-0285 — System 57 analog output module.
The related cards are functionally different even though they belong to the same System 57 hardware family. The relay-card variants add contact outputs, while 05701-A-0326 remains the field interface without relays.
Procurement Verification
Before purchasing a 05701-A-0326, verify:
- Complete part number: 05701-A-0326
- System 57 / 5701 panel compatibility
- Channel position and whether it is the master channel
- Existing single-channel control-card model
- Sensor type and field wiring
- Terminal condition
- PCB revision and physical connector condition
- Whether the replacement is unused, used, or refurbished
- Functional test results where available
Important: Online listings contain several incorrect descriptions of this part, including generic DCS analog I/O, digital-output, and unrelated gas-sensor-module identities. Honeywell’s own System 57 documentation provides the stronger identification: 05701-A-0326 = Field Interface Card, no relays, sensor-to-control-card interface.
