Products for Totally Integrated Automation and Micro ... - Siemens

© Siemens AG 2010SIMATIC S7-1200Analog modulesSM 1231 Thermocouple module■ Overview• To measure temperatures easily and with high accuracy• 7 common thermocouple types can be used• Also for measurement of analog signals with low level(±80 mV)• Easy to retrofit in existing systems■ Field of applicationThe SM 1231 thermocouple module is a highly accurate temperaturesensor using standard thermocouples. Low-level analogsignals in the range of ±80 mV can also be detected. TheSM 1231 thermocouple modules can be used with the CPU ofthe S7-1200 series.■ ConstructionThe SM 1231 thermocouple modules have the sameconstruction features as other modules in the S7-1200 series:Mounting on DIN rails:• The modules are snapped onto the rails next to the CPU on theright and are connected to each other and to the CPU 12xx bymeans of the integrated backplane bus.• Direct installation:The module can also be screwed directly to the wall using thepre-drilled holes. This installation method is recommended incases of high vibration load.• Thermocouples:In each case, 4 thermocouples of types J, K, T, E, R, S and Ncan be used. They are connected directly to the modulewithout amplifiers.• Installation site• Thermocouple modules should be installed in locations withlow fluctuations in temperature to ensure the highest measurementand repeat accuracy.■ Function• Different measuring ranges:Thermocouples of types J, K, T, E, R, S and N;Analog signal recording ±80 mV.• Testing for open lines.• Faults caused by contact voltages at the connection betweenthermocouple and module are prevented; when recordinganalog signals (±80 mV), the compensation is automaticallydeactivated.• Temperature scale:The measured temperature can be displayed in °C or °F.■ Technical specifications6ES7 231-5QD30-0XB0Product type designation Thermocouple module SM 1231Current consumptionfrom load voltage L+60 mA(no-load), max.from 5 V DC backplane bus, max. 87 mAPower lossPower loss, typ.1.8 WConnection systempluggable IO terminalsYesAnalog inputsNumber of analog inputs 4Max. cable length, shielded 100 m; to sensorCable loop resistance100 ΩRefresh time (all channels) 405 msInput ranges (rated values),voltages• -80 mV to +80 mVYesInput ranges (rated values),thermocouples• Type EYes• Type JYes• Type KYes• Type NYes• Type RYes• Type SYes• Type TYesInput ranges (rated values),resistors• permissible input voltage for 30 Vvoltage input (destruction limit),max.Formation of analog valuesMeasuring principleSigma-DeltaIntegration and conversion time/resolution per channel• Resolution with overrange (bits 16 bits; temperature 0.1 °C / 0.1 °Fincluding sign), max.• Noise suppression for interferencefrequency f1 in Hz85 dB at 50 / 60 / 400 HzRange of conversion values thatcan be displayed• bipolar signals -27 648 to +27 648Errors/accuraciesCold connection point +/-1.5 °CRepeat accuracy in settled state at +/- 0.05 %25 °C (relative to input range)Operational limit over entire temperaturerange• Voltage, related to the output +/- 0.1 %range4Siemens ST 70 N · 20104/75