Product Quick Links

• Data Acquisition
• 
• Data Logger
• 
• Chart Recorder
• 
• Temperature Data Loggers
• 
• Humidity Data Loggers
• 
• Temperature and Humidity Data Loggers
• 
• 4-20 mA Current Loop Data Loggers
• 
• Voltage Data Loggers
• 
• USB Data Loggers
• 
• USB Data Acquisition
• 
• Ethernet Data Acquisition
• 
• Event Data Loggers
• 
• USB DAQ

Find the right product for you
with our Product Screener

DI-942MB

Frequency/Pulse Counter Modules
Periodic or Pulse Waveform Input
Limit Alarms or Discrete Outputs

Standard Modbus RTU protocol with high-speed RS-485 communication (up to 115K bps) Separate microcontrollers on each channel for pulse counting and period measurement Solid-state relay outputs enable local limit alarms or host-controlled on/off switching Bipolar and unipolar input signal support Programmable pulse counter functions Input filtering functions include hysteresis, averaging, debounce, relay time delay, and alarm deadband controls 4-way isolation (input, output, power, network) Watchdog timers provide a failsafe output Self-diagnostics monitor microcontroller activity to detect operational failures (lock-up) and execute a reset to restore communication.

Note: Pricing outside the U.S. will be higher to account for shipping, taxes, duty, currency fluctuation, local warranty and technical support in your country. DI-900MB modules have typical lead times of 1-2 weeks.

Part Number	Description	Price (US)	DATAQ Store
DI-942MB	2-channel frequency/counter input module.	$365	Quantity:

Product Highlights

This signal conditioner is a two-channel analog input module with discrete outputs and Modbus communication. It conditions periodic or pulse waveform inputs and provides solid-state relays for limit alarms or ON/OFF control.

Versatile inputs accommodate many applications using TTL, magnetic pickups, proximity sensors, or a variety of switches (high/low-side transistor, dry contact, open drain, open collector). Bipolar and unipolar waveforms are supported with a selectable input bias that accepts both zero and non-zero crossing signals. Voltage threshold and relative hysteresis are also user selectable.

Inputs may also function as event counters with separate microcontrollers for each channel. The module counts pulses on the positive or negative edge. It can wrap around to zero for continuous counting, latch at a programmed count value (setpoint), or automatically reset itself to zero after reaching a setpoint value. Software controls enable remote resets. A variety of filters help remove noise, jitter, and other mechanical effects to prevent false counts.

The discrete outputs can operate as independent alarms or provide on/off control regulated by the host system. As limit alarms, each output can be set for high and/or low setpoints exclusively tied to an analog input. These low cost modules are ideal for standalone alarms as well as for local backup of the primary control system. See the Circuit Connection Diagrams.

Everything you need to complete your network is available from DATAQ Instruments, Inc. - isolators, signal converters, signal boosters, power sources, and mounting hardware. Check out the Accessories.