1-channel analog input terminal strain gauge, Ex i, TwinSAFE SC ELX3351-0090
Self calibration
Error LED
Measure 
Run LED 
Power contact
+24 V EX
Power contact
0 V EX
+UD
+UR
+UV
-UD
-UR
-UV
Top view 
extended temperature range

ELX3351-0090 | 1-channel analog input terminal strain gauge, Ex i, TwinSAFE SC

ExThe analog ELX3351-0090 input terminal enables direct connection of a resistor bridge or load cell from hazardous areas, Zone 0/20 and 1/21. The terminal can be connected in 4- or 6-wire technology. The ratio between the bridge voltage UD and the supply voltage UR is determined in 16-bit resolution, and the load value is calculated as a process value. Apart from automatic self-calibration (can be deactivated), additional functions such as Tara and Freeze as well as dynamic filters are integrated.

With the aid of the TwinSAFE SC technology (TwinSAFE Single Channel) it is possible to make use of standard signals for safety tasks in any network or fieldbus. To do this, EtherCAT I/Os from the areas of analog input, position measurement or communication (4…20 mA, incremental encoder, IO-Link, etc.) are extended by the TwinSAFE SC function. The properties typical for the signals and the standard functions of the I/O components are retained. TwinSAFE SC I/Os differ optically from standard I/Os by a yellow stripe on the front of the housing.

The TwinSAFE SC technology enables communication via a TwinSAFE protocol. These connections can be distinguished from the usual secure communication via Safety over EtherCAT.

The data from the TwinSAFE SC components is fed via a TwinSAFE protocol to the TwinSAFE Logic, where it can be used in the context of safety-relevant applications. Detailed examples confirmed/calculated by the TÜV SÜD for the correct application of the TwinSAFE SC components and the respective normative classifications can be found in the TwinSAFE application manual.

Technical data ELX3351-0090
Technology resistor bridge, strain gauge
Sensor types resistor bridge, strain gauge
Number of inputs 1, for 1 resistor bridge in full bridge technology
Bridge input resistance 300 Ω…1.5 kΩ
Measuring range UD max. -18…+18 mV
Measuring range UREF max. -12…+12 V
Internal resistance > 25 kΩ (UR, differential), > 1 MΩ (UD, differential)
Input filter limit frequency typ. 3.6 kHz (-3 dB, low pass)
Conversion time typ. 1.6 ms
Resolution 24 bit, 32 bit presentation
Filter 50 Hz, configurable
Measuring error < ±0.5 % (relative to full scale value), self-calibration activ
Power supply UV up to 12 V DC from power contacts, dependent on sensor
Supply voltage electronics 24 V DC (via power contacts), ELX9560 power supply
Current consumption power contacts depends on sensor, min. 20 mA
Current consumption E-bus typ. 85 mA
Supported nominal sensitivity all, parameter resolution: 0.01 µV/V; recommended: 0.5…3 mV/V
Special features self-calibration, dynamic filters, Freeze, TwinSAFE SC
Weight approx. 60 g
Operating/storage temperature -25…+60 °C/-40…+85 °C
Relative humidity 95 %, no condensation
Vibration/shock resistance conforms to EN 60068-2-6/EN 60068-2-27
EMC immunity/emission conforms to EN 61000-6-2/EN 61000-6-4
Protect. class/installation pos. IP 20/see documentation
Approvals/markings CE, UL, ATEX, IECEx, cFMus
Ex marking ATEX:
  II 3(1)G Ex ec [ia Ga] IIC T4 Gc
  II (1)D [Ex ia Da] IIIC
  I (M1) [Ex ia Ma] I
IECEx:
  Ex ec [ia Ga] IIC T4 Gc
  [Ex ia Da] IIIC
  [Ex ia Ma] I
cFMus:
  AIS Class I, II, III, Division 1, Groups A thru G
  Class I, Division 2, Groups A, B, C, D
  Class I, Zone 2, AEx nA [ia Ga] IIC T4 Gc
  Class I, Zone 2, AEx ec [ia Ga] IIC T4 Gc
  [AEx ia Da] IIIC T4
further Ex components  
ELXxxxx EtherCAT Terminals with intrinsic safe in- and output
ELXxxxx-0090 EtherCAT Terminals with intrinsic safe in- and output and TwinSAFE SC
CPXxxxx Multi-touch Panel PCs and multi-touch Control Panels for use in hazardous areas, Zone 2/22