Flow Meters with Various Output Signals

Selecting the right output signal is essential for seamless integration and precise data acquisition across your system. Our portfolio includes flow meters with outputs such as pulse or frequency signals, standardized analog interfaces like 4–20 mA or 0–10 V, and modern fieldbus protocols like CAN bus.

Flow Meters with Pulse and Frequency Signals

Flow meters with pulse or frequency signals deliver a defined number of pulses per volume unit, which can be counted directly without complex evaluation. Typical application areas for these sensors include dosing tasks, batch process control, and precise consumption monitoring across various industrial and process engineering workflows.

TTL Signals (Transistor-Transistor Logic)

TTL outputs deliver high-frequency, precise square-wave signals up to 2 kHz, enabling exceptionally high flow resolution. These signals are ideal for connecting to fast counters and PLC frequency inputs where high temporal resolution is required.

In our portfolio, TTL signals are featured in our VCT precision turbine series for pressures up to 25 bar, the FLT high-pressure turbine series for up to 500 bar, and the ASP retrofittable Smart-Pickoff sensor.

Hall Effect (NPN), Reed & NAMUR

These signals are robust and typically low-frequency. They are well-suited for straightforward counting tasks where reliability and longevity are key. Specialized designs, such as NAMUR sensors, are specifically engineered for hazardous (Ex) areas. An example from our product range is the NSF Beverage mini flow meter, which generates NPN pulses via a Hall effect sensor and holds NSF certification for the beverage industry.

NPN Pulse (Open Collector)

The NPN pulse output (Open Collector) is a widely used standard in which the output transistor switches to ground (GND).

We offer this output option on models such as the Beverage Meter with PVDF housing and sapphire bearings, as well as the FT2 Optica radial turbine flow meter.

NPN / PNP Pulse (Flexible)

Flexibly configurable pulse outputs that can operate as either NPN (switching to ground) or PNP (switching to supply voltage) provide maximum compatibility. You will find this flexibility across many of our products, including the 800 Series, 900 Series, and 1000 Series turbine flow meters, the Process Atrato, Atrato, and MetraFlow ultrasonic sensors, and the Pulsite Link signal converter.

Flow Meters with Analog Signals

Analog signals provide a continuous signal proportional to the flow rate, enabling stepless flow rate monitoring. Primary applications for flow meters with analog outputs include process control loops, remote system status monitoring, and real-time flow rate visualization on displays or control systems.

0–10 V (Voltage Signal)

The 0–10 V signal is a widely established, standardized voltage signal in automation technology. It is ideal for direct connection to analog voltage inputs on PLCs and data acquisition modules. Due to its physical characteristics, this signal type is best suited for applications with short cable runs to minimize potential signal attenuation or interference. We offer this output on the Atrato and MetraFlow ultrasonic sensors, the Pulsite Link converter, and the JUMO flowTRANS MAG H20 electromagnetic flow meter.

4–20 mA (Current Signal)

The 4–20 mA current signal is the industry standard for process engineering and automation. Its primary advantage is exceptional noise immunity, allowing reliable signal transmission over long distances of several hundred meters. This makes it the ideal choice for demanding industrial environments with high potential for electromagnetic interference. Available models include the Atrato and MetraFlow ultrasonic flow meters, the Process Atrato ultrasonic flow meter, the Pulsite Link converter, and the JUMO flowTRANS MAG H20 electromagnetic sensor.

Fieldbus and Digital Communication Protocols

Fieldbus systems and digital protocols enable bidirectional communication between the sensor and control system. Unlike analog or pulse signals, they can transmit not only the primary flow measurement but also secondary parameters like temperature and comprehensive diagnostic data.

CAN Bus (CAN 2.0B High Speed)

CAN bus is a highly robust, real-time communication protocol originally developed for the automotive industry. Thanks to its high reliability and immunity to interference, it has become well established across industrial sectors. It is ideal for automotive testing, mobile machinery, and highly networked systems requiring deterministic, high-speed data transmission. Combined with our flow meters, our VCA-CAN Flow Computer enables direct CAN bus output integration.

IO-Link

IO-Link is a modern, flexible point-to-point communication interface recognized as the digital standard for smart manufacturing. It enables high-resolution process data transmission alongside diagnostic parameters and remote sensor configuration directly via the PLC, significantly simplifying commissioning and maintenance. Our JUMO flowTRANS MAG H20 electromagnetic flow meter features an IO-Link interface alongside Bluetooth and NFC connectivity options.

Which Output Signal Is Right for My Application?

This decision guide summarizes the main characteristics of each signal type to help you make the right choice:

Signal Type	Advantages	Disadvantages
Pulse / Frequency	Simple, cost-effective, highly accurate for totalizing flow volumes.	Susceptible to interference over long cable runs; transmits flow data only.
Analog (4–20 mA / 0–10 V)	Established industry standard, highly immune to EMI (4–20 mA), ideal for long distances.	Transmits only one measured value per line; no extended diagnostic capabilities.
Fieldbus / Digital (CAN Bus, IO-Link)	Transmits multi-variable data (flow, temperature, diagnostics), bidirectional communication, future-proof.	Requires higher integration effort and specialized controller programming.

Get Expert Advice on Flow Meter Output Signals

At DDM Sensors, our engineering team is ready to consult with you to determine the ideal output signal and flow meter solution for your specific application requirements.