Honeywell 621-3560 (6213560) Product Description

621-3560 (6213560) is a 16-channel, 24V DC current-type (6–15mA) source-type digital input module (DI) of the Honeywell 621 series I/O, specially designed for low-power consumption and high-interference resistance in industrial signal acquisition. 

I. Basic Information

Brand: Honeywell (Honeywell / ISSC)

Full Model: 621-3560 (6213560)

Series: 621 Series I/O Module (IPC 620 / 621, TDC 3000, UCN System)

Type: 16-channel 24V DC Current-Type (6–15mA) Source-Type Digital Input Module (DI)

Production Status: Out of Production (Second-hand / Repaired / Refurbished Channel)

Weight: Approximately 0.2–0.25 kg

Size: Approximately 120 × 30 × 150 mm

Installation: Inserted into the 621 Series I/O Rack

Isolation: Channel - System Side Photoelectric Isolation

Common Suffix:

621-3560R: Supports Hot Swap

621-3560RC: Hot Swap + Enhanced Protection

II. Core Functions

16-channel Current-Type 24V DC Input: Low-power design, suitable for long-distance transmission

Current Detection Logic (6–15mA): High anti-interference, avoiding voltage signal false triggering

Source-Type Input: Suitable for PNP-type sensors, two-wire transmitters

Photoelectric Isolation: 1500V AC RMS Isolation, protecting the system side safety

LED Status Indication per Channel: Real-time monitoring of signal on/off

Overvoltage / Reverse Connection / Overcurrent Protection: Built-in protection circuit to prevent wiring errors from damaging the module

Standard Scan Time: ≤ 10 ms for Full Channel Scan

Compatible Systems: IPC 620, IPC 621, TDC 3000, UCN, etc. legacy DCS

III. Electrical Specifications

Input Voltage: 18–28 V DC (Nominal 24V DC)

Channel Count: 16 Channels (Independent)

Input Type: Source-Type / PNP Type / Current-Type (6–15mA)

Current Threshold: ≥ 6mA = ON, ≤ 1mA = OFF

Compatibility: Two-wire sensors, PNP Proximity Switches, Dry Contacts (Series Limiting Resistor)

Input Current: 6–15 mA (Working)

Leakage Current: ≤ 1 mA (Off)

Isolation Voltage: 1500V AC RMS (Channel - System Side)

Scan Time: ≤ 10 ms (Full Channel)

Power Consumption: Approximately 3.5 W

Power Supply: 5V DC (Backplane Bus Power Supply)

Input Resistance: ≈ 2.4 kΩ

IV. Environmental Parameters

Operating Temperature: 0°C ~ +60°C

Storage Temperature: -40°C ~ +85°C

Humidity: 5–95% RH (No Condensation)

Anti-Vibration: 10–55 Hz, 0.7 mm Double Amplitude

Protection: IP20 (Installed in Cabinet)

Certifications: CE, UL, CSA

V. Interfaces and Status

Field Interface: 50-pin D-Sub / European Terminal Block

LED Indicators:

PWR: Green (Normal Power Supply)

16-channel LED: On = ON, Off = OFF

COM: Red (Common Port Abnormal / Bus Fault)

Bus Interface: 621 Rack-Specific Parallel Bus

VI. Typical Applications

Low-power 24V DC Signal Acquisition: Two-wire sensors, PNP Proximity Switches, Long-distance Dry Contacts

High-interference Industrial Environment: Power Plants, Petrochemicals, Metallurgy, Mining, etc. Strong Electromagnetic Interference Scenarios

Current-Type Signal Monitoring: Transmitter Status, Safety Barrier Output, Intrinsically Safe Loop Signals

Old System Upgrade: IPC 620 / 621, TDC 3000 System DI Module Replacement

VII. Model Comparison (621 Series DI) Table

Parameters: 621-3550, 621-3560, 621-3552

Number of channels: 16 channels, 16 channels, 16 channels

Voltage: 24V DC, 24V DC, 24V DC

Input type: Voltage type (source type), Current type (6–15mA, source type), Voltage type (source type)

Response time: ≤ 10 ms, ≤ 10 ms, ≤ 1 ms

Features: Standard voltage input, current detection, high anti-interference, fast response, high speed

VIII. Common Faults and Troubleshooting

No input on the channel (LED does not light up)

Reason: Loose wiring, no current output from the sensor, missing current-limiting resistor, current < 6mA

Troubleshooting: Measure the circuit current, check the sensor power supply, replace the channel/module

LED constantly on (false trigger)

Reason: Short circuit in the line, excessive leakage current, module internal fault

Troubleshooting: Disconnect the signal for testing, check the grounding, replace the module

Hot swapping (R type) failure

Reason: Rack does not support hot swapping, module not securely inserted, bus abnormality

Troubleshooting: Confirm that the rack supports hot swapping, reinstall, clean the interface

IX. Related Models

Standard 24V DC source type voltage input: 621-3550 (16 points)

Fast 24V DC source type voltage input: 621-3552 (16 points, high speed)

12V DC leakage input: 621-3450 (16 points)

Fast DI module: 621-3502 (8 points, 12–24V high speed)

115V AC input: 621-1160 (16 points), 621-1101 (6 points isolation)

Digital output: 621-2100, 621-2101, 621-2150

Hot swapping series: 621-xxxxR (R = hot swapping)

Analog input: 621-4000, 621-4001