1-, 2-channel thermocouple input terminals with open-circuit recognition EL3311
Error LED 1
Run LED1 
Power contact
+24 V
Power contact 0 V
+TC1
GND
Shield
-TC1
GND
Shield
Top view 
Contact assembly 
Observe for earthed
thermocoupler:
differential inputs
max. ± 2 V to ground
extended temperature range
extended shock and vibration range
1-, 2-channel thermocouple input terminals with open-circuit recognition EL3312
Error LED 2
Error LED 1
Run LED2 
Run LED1 
Power contact
+24 V
Power contact 0 V
+TC1
+TC2
GND
Shield
-TC1
-TC2
GND
Shield
Top view 
Contact assembly 
Observe for earthed
thermocoupler:
differential inputs
max. ± 2 V to ground
extended temperature range
extended shock and vibration range

EL3311, EL3312 | 1-, 2-channel thermocouple input terminals with open-circuit recognition

The EL3311 and EL3312 analog input terminals allow thermocouples to be connected directly. The EtherCAT Terminals circuit can operate thermocouple sensors using the 2-wire technique. Linearisation over the full temperature range is realised with the aid of a microprocessor. The temperature range can be selected freely. The error LEDs indicate a broken wire. Compensation for the cold junction is made through an internal temperature measurement at the terminals. The EL3311/EL3312 can also be used for mV measurement.

Technical data EL3311 EL3312
Number of inputs 1 2
Power supply via the E-bus
Thermocouple sensor types types K, J, L, E, T, N, U, B, R, S, C (default setting type K), mV measurement
Distributed clocks
Input filter limit frequency typ. 1 kHz; dependent on sensor length, conversion time, sensor type
Connection method 2-wire
Wiring fail indication yes
Conversion time approx. 750 ms up to 20 ms, depending on configuration and filter setting, default: approx. 75 ms approx. 1.2 s up to 20 ms, depending on configuration and filter setting, default: approx. 125 ms
Temperature range in the range defined in each case for the sensor (default setting: type K; -200…+1,370 °C); voltage measurement: ±30 mV…±75 mV
Resolution 0.1 °C per digit
Measuring error < ±0.3 % (relative to full scale value)
Electrical isolation 500 V (E-bus/signal voltage)
Current consumption power contacts
Current consumption E-bus 200 mA
Bit width in the process image 1 x 32 bit TC input, 1 x 16 bit TC output 2 x 32 bit TC input, 2 x 16 bit TC output
Special features open-circuit recognition
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/variable
Approvals CE, UL, Ex