Description
Honeywell FC-SDI-1624 Safe Digital Input Module
Product Introduction
In a Safety Manager installation, the digital input card is the point where field status signals become validated logic for the safety application. Honeywell FC-SDI-1624 is a 16-channel safe digital input module designed for 24 VDC field signals. Honeywell’s hardware documentation identifies FC-SDI-1624 as the conformal-coated version of the SDI-1624 family, with defined input thresholds and a 36 VDC maximum input voltage.
The important procurement detail is the FC designation. Honeywell specifies FC-type modules as conformal-coated, while FS-type modules are the non-conformal-coated version. The documented module also has 5 VDC and 24 VDC power requirements and a 24 VDC solid-state output associated with the input circuitry. This makes exact type and revision matching more important than simply searching for an “SDI-1624” card.
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | FC-SDI-1624 |
| Manufacturer | Honeywell |
| Product Family | Safety Manager |
| Product Type | Safe Digital Input Module |
| Input Channels | 16 |
| Nominal Input Voltage | 24 VDC |
| Maximum Input Voltage | 36 VDC |
| Input Current | 7 mA at 24 VDC |
| Input HIGH Threshold | >15 VDC |
| Input LOW Threshold | <9 VDC, I <2 mA |
| Typical Input Delay | 10 ms |
| Module Supply | 5 VDC, 8 mA |
| Internal 24 VDC Supply | 110 mA |
| External 24 VDC Input Current | 110 mA |
| Solid-State Output | 24 VDC, short-circuit protected |
| Maximum Output Current | 450 mA |
| Maximum Load Capacitance | 32 µF |
| Output Voltage Drop | <1.5 V at 450 mA |
| Approvals | CE, TÜV, UL, CSA, FM |
| Module Size | 4 TE × 3 HE (4 HP × 3U) |
| Coating | Conformal-coated FC version |
The specifications above are taken from Honeywell’s Safety Manager hardware documentation. In particular, the designation appears in Honeywell’s type-number documentation; do not automatically treat an unmarked or FS- as the same physical variant.
Application Scenarios & Field Considerations
Safety Manager Digital Input Acquisition
The module is intended for digital field signals in a Honeywell Safety Manager installation. Typical engineering work involves monitoring discrete process or safety-related states and passing those signals into the safety system for application logic.
FC-SDI-1624
Legacy Safety System Maintenance
For an installed Safety Manager system, is more than a generic 16-point digital input card. The module type, coating designation, connector coding, and system chassis compatibility all matter. Honeywell specifies A5/C5 coding for both the module connector and chassis connector.
Replacement During Plant Shutdown
This type of module is commonly relevant when maintaining an existing safety system where the original hardware is no longer readily available through normal project channels. Before replacing a failed card, compare the complete type marking and revision rather than ordering solely from the abbreviated “” family name.
Conformal-Coated Installations
The FC designation identifies the conformal-coated version. This distinction can matter in procurement because Honeywell documents the FS version as non-conformal-coated and the FC version as conformal-coated. They should not be treated as interchangeable simply because both carry the designation.
Related Products
- — non-conformal-coated variant; verify chassis and project requirements before substituting.
- FC-SDO-0824 — Honeywell Safety Manager safe digital output module; different signal direction and function.
- FC-SDOL-0424 — safe digital output/logic module family; not a replacement for an SDI card.
- FC-SAI-1620M — safe high-density analog input module; intended for analog rather than discrete signals.
- FC-SAO-0220M — safe analog output module; different I/O function.
- Safety Manager I/O Chassis — host hardware must match the module’s mechanical coding and system architecture.
These related part numbers should be used as functional references, not as automatic substitutions. Exact Safety Manager configuration and module revision should be checked against the project hardware documentation.
Engineer’s Guide — Field Pitfalls to Avoid
1. Do not confuse FC with FS.
Honeywell explicitly distinguishes FC conformal-coated modules from FS non-conformal-coated modules. If the plant BOM specifies FC-, buying an FS- based only on the common suffix is a procurement error.
2. Check the actual input threshold.
A 24 VDC label does not mean that every voltage above 0 V will be recognized as ON. The documented HIGH threshold is above 15 VDC, while LOW is below 9 VDC under the specified current condition. Field transmitter and contact circuits should be checked against these limits.
3. Do not treat the card as a generic PLC DI module.
The FC- is specifically documented within the Honeywell Safety Manager hardware family. Connector coding and chassis compatibility are part of the installation requirement.
4. Verify the complete type number.
Honeywell’s documentation lists as the conformal-coated type number. If the physical card carries a different revision or suffix, record it before placing a replacement order.
5. Check the field power architecture.
The module documentation specifies both 5 VDC and 24 VDC power requirements. Do not assume that the field 24 VDC supply is the only power requirement for the card.
6. Inspect the module before installation.
For an older Safety Manager card, inspect the connector, keying, coating condition, terminal interface, PCB contamination, and identification labels. For stocked spare hardware, actual inventory condition should be verified rather than inferred from the part number.
FAQ
What is Honeywell FC-?
It is a 16-channel safe digital input module for the Honeywell Safety Manager system, designed around 24 VDC digital input signals. Honeywell’s hardware reference identifies FC- as the conformal-coated variant of the module family.
Is FC- a 24 VDC input module?
Yes. Honeywell identifies the as a 24 VDC, 16-channel safe digital input module. The documented maximum input voltage is 36 VDC, with HIGH recognition above 15 VDC and LOW recognition below 9 VDC under the specified condition.
What is the difference between FC- and FS-?
The key documented difference is the coating. FC identifies the conformal-coated module, while FS identifies the non-conformal-coated version. The two should not be substituted without confirming the plant’s approved hardware configuration.
How many digital inputs does FC- provide?
The module provides 16 digital input channels. Honeywell specifies a typical input delay of approximately 10 ms.
What is the maximum input voltage?
The documented maximum input voltage is 36 VDC. The nominal field input is 24 VDC. Applying a higher voltage simply because the system supply is available is not an acceptable commissioning practice.
Does FC- require a specific Safety Manager chassis?
Yes. Mechanical key coding is documented for the module and chassis connectors, with A5/C5 coding specified. The module should therefore be checked against the exact Safety Manager chassis and project hardware configuration before installation.
What should procurement verify before buying a replacement?
At minimum, verify , the complete version/revision marking, FC conformal-coating designation, connector/key coding, physical condition, and the existing Safety Manager chassis configuration. If the replacement is intended for a safety-critical shutdown system, compare the card against the approved hardware documentation rather than relying on a generic “16-channel 24 VDC DI” description.
