DS3800HFPB | 8-Channel High-Speed Pulse Input Board

Description

Product Introduction

The DS3800HFPB is the frequency input board for the Mark V—it captures high-speed pulse signals from speed sensors, flow meters, and tachometers. This board is designed for applications where you need to measure frequency, count pulses, or detect speed changes. It accepts 120V AC or DC signals, making it compatible with a wide range of field sensors. The 8-channel capacity is sufficient for most turbine applications, where you typically monitor one or two speed signals per shaft.

We’ve used the HFPB to measure turbine speed from magnetic pickup sensors that output a 120V AC signal proportional to speed. The board’s frequency range (0-10kHz) covers the typical speed range of 60Hz turbines (up to 7.2kHz for a 120-tooth gear). The 12-bit resolution provides a count value that the Mark V uses for speed calculations and overspeed protection. The status LEDs show the input state, helping with troubleshooting. The board’s backplane current draw is 1.0A, typical for this class of input board.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: What’s the difference between the HFPB and a standard discrete input board?
A: The HFPB is designed for high-speed pulse signals (frequency), while standard discrete inputs are for slow-changing signals (e.g., pushbuttons, limit switches). The HFPB has a higher bandwidth (10kHz) and includes frequency/count measurement circuitry. The HDDA, for comparison, is for static 120V AC inputs and has a 10ms response time but no frequency measurement.

Q: Can I use the HFPB with a magnetic pickup sensor that outputs a 120V AC signal?
A: Yes, the HFPB is designed for 120V AC inputs, making it compatible with most magnetic speed sensors used on turbines. The board’s input impedance is 10kΩ, which is typical for these sensors. If your sensor outputs a different voltage (e.g., 24V DC), you may need a different board or an external signal conditioner.

Q: What’s the frequency range of the HFPB?
A: The HFPB can measure frequencies from 0Hz to 10kHz. For a 60Hz turbine with a 120-tooth gear, the sensor frequency is 60Hz × 120 = 7.2kHz, which is within the board’s range. The board’s 12-bit resolution provides a count that the Mark V uses to calculate speed.

Q: How does the HFPB measure frequency?
A: The HFPB counts pulses over a fixed time interval (typically 10ms) and provides a count value to the Mark V. The Mark V calculates frequency by dividing the count by the time interval. The board also has filter jumpers to debounce noisy signals (3ms or 10ms filter). For speed measurement, you typically use the 3ms filter for faster response.

Q: Can I use the HFPB for flow meter pulse counting?
A: Yes, the HFPB can count pulses from flow meters that output a 120V AC signal. The count value can be used for totalization or rate measurement. However, the 10ms scan rate may not be sufficient for high-frequency flow meters (>10kHz). Check your flow meter’s output frequency before choosing the HFPB.

Q: The HFPB has a 1.0A backplane current draw. Is that typical for this board?
A: Yes, the 1.0A draw is typical for frequency input boards due to the optical isolation and input conditioning circuitry. The Mark V power supply is rated at 6A on the 5V rail, so the HFPB is within the limit. If your rack has multiple HFPB boards, check your total backplane current.

Q: Does the HFPB have conformal coating?
A: Not by default. The HFPB’s suffix typically indicates termination type, not coating. If you need conformal coating for harsh environments, look for a suffix with a “G” (e.g., DS3800HFPB1G1G). The standard HFPB is suitable for indoor environments. If your plant has high humidity or corrosive conditions, consider a coated variant.

GE DS200TCCAP1BAD
GE DS200TCCBF1ACA
GE DS200TCCBF1ACB