Hydac EDS 824-F31-0400-000 IO-Link Pressure Switch, 400 bar

High-pressure switching and IO-Link diagnostics in a 65 g body

The Hydac EDS 824-F31-0400-000 (HYDAC part number 925909) is a compact electronic pressure switch for the high-pressure range with an IO-Link interface. It has two PNP transistor outputs, one of which can double as the IO-Link communication line. Through IO-Link the control can read process data, parameterise the switch and collect diagnostic information over a standard unshielded sensor cable.

HYDAC names machine tools, handling and assembly automation, intralogistics and packaging as typical fields for the EDS 820 series. This code covers 0 to 400 bar with a G1/4 A port that has a 0.5 mm orifice.

Technical specifications

IO-Link benefits

With IO-Link the parameters of the switch (set points, hysteresis, delays) can be stored in the IO-Link master and downloaded automatically when a device is exchanged, which shortens replacement time. The IODD device description is available from the IO-Link finder website. The same device also works in plain SIO mode as a switch, so it can be used with controllers that have no IO-Link master.

Ordering code

The datasheet pattern is EDS 8 2 7 – XXXXX – F31 – 000 (PSI): 7 selects the SAE-6 thread in the USA edition, F31 selects the IO-Link output and 000 is the standard modification. The bar item listed in the HYDAC catalogue as EDS 824-F31-0400-000 has a G1/4 A port and a 0 to 400 bar range. Confirm the process connection before you order, since SAE-6 and G1/4 are not interchangeable.

Because the pressure switch has an orifice in the port, pressure peaks and pulsation are damped before they reach the sensor cell, which suits hydraulic pump lines. Use a standard M12 sensor cable of up to 20 metres for IO-Link, and check the IODD version when integrating the device in the engineering tool.

The IO-Link interface lets a controller read the pressure value and change parameters over a standard three-wire sensor cable. Check that your IO-Link master supports the data rate and process data length listed in the datasheet before choosing this variant.

Selecting this switch for a hydraulic circuit

The EDS 824-F31-0400-000 is a sensible choice where a machine needs a pressure-dependent switching signal and, at the same time, a continuous pressure value for the controller. The two PNP outputs can be used for two independent set points, for example a pressure-reached signal and a warning threshold, while the IO-Link line carries the measured value and diagnostics to the master. Where only one switching signal is needed, the second channel remains available for later changes in the control logic without replacing the device.

When comparing measuring ranges, base the choice on the normal working pressure of the circuit and on the peaks the line can see during valve switching. The operating range, overload pressure and burst pressure given in the table should be compared with the pressure profile of the system, not only with the nominal pump setting. If the working pressure sits well below the upper part of the range, consider whether a different range from the same series would give better resolution of the set points.

Typical application context

In machine tools, handling and assembly automation, intralogistics and packaging, the switch is typically placed on clamping circuits, accumulator lines, pump outlets or lubrication supplies, where a missing or excessive pressure must stop or release a machine sequence. The stainless steel housing and IP 67 protection suit installation directly on the hydraulic block or manifold, close to the point being monitored. The damping orifice in the port helps when the switch sits close to pumps or fast-acting valves.

Because parameters can be held in the IO-Link master, the same switch type can serve several positions on a machine with different set points, which simplifies spare-part handling for machine builders and plant maintenance teams.

Installation and commissioning considerations

Mount the switch on a clean, correctly machined G1/4 port and tighten it to the torque stated in the table. Route the M12 sensor cable away from power cables and moving parts and provide strain relief. Before pressurising the circuit, check the supply voltage range and the wiring of pin 4, since this pin is either a switching output or the IO-Link line depending on the operating mode.

During commissioning, load the matching IODD into the engineering tool, set the switch points, hysteresis and delays, and verify each output against a reference gauge under real operating conditions. Confirm that the yellow LEDs for SP1 and SP2 follow the expected switching behaviour and that the green operating LED is on. Store the final parameter set in the IO-Link master so that it can be restored automatically if the device is exchanged later.

How to specify your request for quotation

To avoid ambiguity, quote the full model code EDS 824-F31-0400-000 together with the HYDAC part number 925909. State the required process connection, since the G1/4 A version and the SAE-6 USA edition are different items. Describe the medium, the normal and maximum system pressure, the fluid and ambient temperature, and whether the switch will run in IO-Link or SIO mode. Include the make and type of your IO-Link master and the quantity required, so that compatibility and the correct variant can be checked before an offer is prepared.

Documents and quotation

The EDS 820 IO-Link datasheet (E 18.070.1.0/11.13) is attached. Send the complete code and master details. See also our pressure instrumentation range.