Description
The EOMF is a two-channel measuring transducer with a built-in overload circuit of level PL c / SIL 1, type MEUTS-SIL, certified by TÜV Nord under number 44 799 14098202.
Its special feature is the safety circuit: it has its own amplifier and runs parallel to the measurement chain of the IO-Link transducer – meaning the safety function is not dependent on the measurement chain. A solid-state relay opens if the switching point is exceeded, if the measuring amplifier's supply voltage is too low or missing, if there is a cable break on one or both signal lines, and if the safety circuit's own supply is too low or missing. The safe state is the open relay. The input is high-impedance biased to detect a cable break; two comparators – one for the measuring signal against the switching point, one for the bridge supply – are AND-linked.
Two limit values can be set via IO-Link: the turn-on point from -7 to +7 mV, the turn-off point from -5 to +21 mV, with a switching accuracy of ± 50 µV and a reaction time of a maximum of 10 ms. The switching load is a maximum of 30 VAC/VDC at 500 mA. It is based on EN ISO 13849-1:2015 and EN 61508:2010.
Channel 1 measures a full strain gauge bridge, dimensionless, from 350 Ω (two bridges from 2 × 700 Ω) with a bridge supply of 3 V. Channel 2 is universal, pre-set to °C, for Pt100 in 3-wire circuit from -200 to 800 °C at 0.9 mA or a thermocouple of type J (-210 … 1200 °C), type K (-200 … 1372 °C) or type N (-200 … 1300 °C). The range of both channels is freely adjustable in the range -3200.0 … +3200.0.
The output provides IO-Link with level 0 / 24 V and a current output 4 … 20 mA, which runs via input 1. The resolution is 16 bit on the strain gauge channel and 24 bit on the universal channel, with an accuracy of max. 0.05 % of the measuring range plus sensor error. Filter: 0.5 s for strain gauge, 25 s for temperature. Supply 24 VDC at under 30 mA in standard operation, maximum 130 mA total current.
The board measures 21 × 76.95 × 4.2 mm and weighs approximately 7.6 g, material FR4 and PBT, connection via solder pads 2.7 × 1.5 mm, mounting position optional, operating range -20 °C to +80 °C.
Three mounting requirements and the enabling of the limit values must be read before the housing is closed. The board must be installed in the sensor housing to at least IP54 and protected against vibrations; the safety circuit must be regularly checked for function, the manufacturer recommends two years, and the limit values must be checked before commissioning. To set the limit values via IO-Link, a phototransistor (SFH 309 or similar) must be connected and illuminated; thereafter, the settings must be read back and the phototransistor darkened – in normal operation, it must be covered in such a way that unintentional illumination is excluded.
An IO-Link master is required for configuration and operation, as well as the IODD file from the IODD finder. The board has been tested according to EN 61000-6-2:2005 and EN 61000-6-4:2007. A CE mark is not documented in the manufacturer's data sheet; a declaration of conformity must be requested before placing on the market in the EU. The version without safety function is the EOME.
Regarding price: The price applies to the basic version of the board. Measuring ranges and limit values are adjustable via IO-Link, so factory programming is not required. If you would like the board factory-programmed to your measuring ranges and switching points, this is possible at an additional cost — please ask us.
Advantages at a glance
- Overload circuit PL c / SIL 1, TÜV Nord 44 799 14098202
- Safety circuit with its own amplifier, parallel to the measuring chain
- Relay also opens in case of cable break and undervoltage – safe state is open
- Two limit values adjustable via IO-Link, reaction time max. 10 ms
- Outputs IO-Link and 4 … 20 mA
- Channel 1 full strain gauge bridge, Channel 2 Pt100 or thermocouple
- Resolution 16 bit strain gauge, 24 bit universal, accuracy max. 0.05 %
- 21 × 76.95 × 4.2 mm, approx. 7.6 g, operating range -20 … +80 °C