4-channel thermocouple input terminal with open-circuit recognition KL3314
Error LED1
Error LED3
Error LED2
Error LED4
+TC1
-TC1
+TC3
-TC3
+TC2
-TC2
+TC4
-TC4
Top view 
Contact assembly 
Observe for earthed
thermocoupler:
differential inputs
max. ± 2 V to ground
extended shock and vibration range

KL3314 | 4-channel thermocouple input terminal with open-circuit recognition

The KL3314 analog input terminal allows four thermocouples to be connected directly. The Bus Terminal’s circuitry can operate thermocouple sensors using the 2-wire technique. Linearisation over the full temperature range, which can be selected freely, is realised with the aid of a microprocessor. The error LEDs indicate a broken wire. Compensation for the cold junction is made through an internal temperature measurement at the terminals. The KL3314 can also be used for mV measurement.

Technical data KL3314
Number of inputs 4
Power supply via the K-bus
Technology 2-wire
Thermocouple sensor types types J, K, L, B, E, N, R, S, T, U (default setting type K), mV measurement
Connection method 2-wire
Measuring range in the range defined in each case for the sensor (default setting: type K; -100…+1,370 °C);
mV measurement: ±30 mV…±120 mV
Conversion time ~ 250 ms
Wiring fail indication yes
Resolution 0.1 °C per digit
Measuring error < ±0.5 % (relative to full scale value)
Electrical isolation 500 V (K-bus/signal voltage)
Current consumption power contacts – (no power contacts)
Current consumpt. K-bus typ. 75 mA
Bit width in the process image input: 4 x 16 bit data (4 x 8 bit control/status optional)
Configuration no address setting, configuration via Bus Coupler or controller
Weight approx. 75 g
Operating/storage temperature 0…+55 °C/-25…+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, GL
Further information www.beckhoff.com/KL3314