Honeywell 51404351-175 TK-MDP081 Pulse Input Module

Precision Pulse Acquisition for Flowmeters and Rotary Encoders

The Honeywell 51404351-175 TK-MDP081 pulse input module offers eight independent channels for frequency measurement. This module accurately counts pulses from turbines, flowmeters, and encoders. It also measures frequency and totalizes events from field devices. You can rely on this module for precise rate calculations in critical applications. Its robust design ensures reliable operation in noisy industrial environments.

Input Characteristics and Signal Processing

Each channel accepts a wide range of input signal types. The module supports dry contact, voltage, and current inputs. It also includes programmable debounce filtering for switch contacts. This filtering eliminates false counts from contact bounce. The module features a high maximum input frequency for fast pulse trains. It also provides a low-frequency mode for slow-speed sensors.

Key Technical Specifications

Parameter	Specification
Manufacturer	Honeywell Process Solutions
Model	51404351-175 TK-MDP081
Product Type	Pulse Input Module
Number of Channels	8 (Isolated)
Input Types	Dry Contact, Voltage (5-30 VDC), Current (4-20 mA)
Maximum Frequency	10 kHz (High-Speed Mode)
Minimum Frequency	0.01 Hz (Low-Speed Mode)
Pulse Width Requirement	> 50 µs (High Speed); > 50 ms (Low Speed)
Input Impedance	3.3 kΩ (Voltage Mode); 250 Ω (Current Mode)
Debounce Filter	0 to 100 ms (Programmable)
Count Range	32-bit (0 to 4,294,967,295)
Accuracy	±0.01% of Reading
Isolation Voltage	1500 VAC (Channel to Backplane)
Power Consumption	5 VDC: < 200 mA; 24 VDC: < 100 mA
LED Indicators	Channel Active, Pulse Present
Dimensions	28.5 cm x 17.8 cm x 5.5 cm (H x W x D)
Weight	Approximately 0.8 kg
Termination Assembly	Requires separate TA for field wiring
Operating Temperature	0°C to 60°C
Storage Temperature	-40°C to 85°C
Relative Humidity	5% to 95% (Non-condensing)

Frequency Measurement and Totalization Capabilities

The module simultaneously measures frequency on all eight channels. It also accumulates total pulse counts for each input independently. The module stores these totals in non-volatile memory for data retention. This memory preserves count values during power loss events. The module also supports programmable scaling for engineering units. You can directly read flow rates in liters per minute.

Signal Conditioning and Noise Immunity

The module employs opto-isolation to protect the backplane from field transients. This isolation prevents ground loops and common-mode noise interference. The module also includes a built-in signal conditioner for each channel. This conditioner converts raw pulses into clean logic signals. Furthermore, its high noise immunity ensures accurate counting in electrically noisy areas.

Physical Dimensions and Interface Connections

This module measures 28.5 cm in height and 17.8 cm in width. Its depth is 5.5 cm for standard rack installation. The device weighs approximately 0.8 kilograms. It interfaces with field devices via a separate Termination Assembly. This assembly provides convenient screw terminals for each channel. The front panel houses eight LED status indicators. These LEDs show pulse activity for each input channel.

Installation, Configuration, and Application Notes

You can install the 51404351-175 TK-MDP081 into any TDC 3000 rack slot. Configuration involves setting jumpers for input type selection. Software then defines the frequency range and scaling parameters. This module suits flow totalization in custody transfer applications. It also provides speed monitoring for rotating machinery. Additionally, the module serves position feedback from linear encoders.