Description
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Honeywell |
| Model | SAI-1620m |
| Product Type | Safe high-density analog input module |
| System | Honeywell Safety Manager |
| Number of Channels | 16 analog inputs |
| Input Range | 0–4.1 V |
| A/D Converter | 12-bit |
| A/D Inaccuracy | ±1 LSB |
| Module Inaccuracy | <0.25% |
| Maximum Input Signal | ±36 VDC |
| Input Resistance | >1 MΩ |
| Cross Talk | >60 dB |
| External Voltage Readback | 0–4.1 V |
| Readback Input Resistance | Typically 1 MΩ |
| Power Requirement | 5 VDC / 24 VDC versions depending configuration |
| Module Width | 4 TE |
| Module Height | 3 HE / 3U |
| Typical Safety Application | Safety Manager SIS |
The technical data identifies 16 channels, a 0–4.1 V input range, 12-bit conversion, ±1 LSB A/D inaccuracy, and less than 0.25% module inaccuracy.
Honeywell’s Safety Manager revision documentation also identifies the SAI-1620m family as a safe high-density analog input module with 24 VDC, 16 channels, including FA and FC conformal-coated variants.
Product Introduction
The Honeywell SAI-1620m is a 16-channel safe analog input module used in the Honeywell Safety Manager platform. Unlike a conventional PLC analog input card, its signal path is designed for safety-system use, with module diagnostics and controlled self-testing handled by the Safety Manager architecture.
A critical point during system maintenance is the distinction between the SAI-1620m module and the TSAI-1620m field termination assembly. The SAI-1620m expects a low-level voltage signal, while TSAI-1620m converts 0/4–20 mA field signals and provides the appropriate interface to the SAI-1620m.
SAI-1620M
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
The most common identification error is treating SAI-1620m as a conventional 0/4–20 mA analog input card. It is not. The direct SAI-1620m input is approximately 0–4 V, so the field current signal requires the appropriate conversion/interface arrangement.
Typical Applications
- Safety Instrumented Systems — acquisition of process measurements used by Safety Manager logic.
- Emergency shutdown systems — monitoring pressure, temperature, flow, and other safety-related analog variables.
- Fire and gas systems — when used with the appropriate Honeywell field interface.
- Process protection applications — high-density analog measurement within Honeywell Safety Manager installations.
Technical Pitfalls to Avoid
- Do not wire a 4–20 mA transmitter directly to the SAI-1620m without checking the interface architecture.
Honeywell documentation identifies TSAI-1620m and other dedicated termination/conversion modules as methods for converting field 0/4–20 mA signals to the SAI-1620m input level. - Do not confuse SAI-1620m with TSAI-1620m.
TSAI-1620m is the field termination assembly: it has 16 current-input channels, 250 Ω input resistance, 30 VDC external power, and provides a 0–4 VDC output toward the SAI-1620m. - Verify the exact revision and coating designation.
Honeywell Safety Manager certification records distinguish FA and FC versions and different hardware revisions. FA versions are associated with ATEX configurations, while FC versions are conformal-coated configurations. - Do not approve a replacement solely from the SAI-1620m family name.
Confirm the complete catalog designation, hardware revision, Safety Manager chassis, associated termination module, and existing safety certification basis.
Related Products
- Honeywell TSAI-1620m — 16-channel safe 0/4–20 mA field termination assembly used to convert transmitter signals for SAI-1620m.
- Honeywell TSHART-1620m — 16-channel analog termination arrangement with HART interface.
- Honeywell TSGAS-1624 — dedicated gas/flame detector interface associated with the SAI-1620m architecture.
- Honeywell TSFIRE-1624 — fire-detector interface with line monitoring.
- Honeywell BSAI-1620mE — analog input conversion module mounted at the I/O backplane programming connector.
- Honeywell SAI-0410 — smaller safe analog input module with four channels.
- Honeywell Safety Manager Controller — safety controller responsible for module diagnostics and system-level processing.
- Honeywell SDIL-1608 — safe line-monitored digital input module with 16 channels.
Procurement Check
For a SAI-1620m replacement, verify these items before approval:
SAI-1620m → 16-channel safe analog input
Input → 0–4 V class, not a direct 4–20 mA input
Termination → confirm TSAI-1620m, TSHART-1620m, TSGAS-1624, TSFIRE-1624, or BSAI-1620mE arrangement
Revision → verify FA/FC designation and hardware revision
Safety certification → match the installed Safety Manager configuration
One final procurement warning: several current web listings incorrectly describe SAI-1620m as a generic 220 VAC drive or industrial drive module. Those specifications do not match the Honeywell Safety Manager technical documentation and should be rejected when identifying this part.
