Siemens Simatic S7 Series Manual page 70

Expansion Modules for
Temperature Measurement
EM 231 Thermocouple module, 4 Input Version
Two.S7-200.PLC.expansion.modules.are.available.for.accurate
temperature.measurement, EM 231 Thermocouple module
and EM 231 RTD module.
EM.23.Thermocouple.module.provides.analog.inputs.for.
thermocouples..A.thermocouple.is.a.temperature.sensor.
made.from.two.dissimilar.metals.joined.at.a.point.called.a.
junction..A.thermocouple.produces.a.small.voltage.that.is.
dependent.upon.temperature..Various.types.of.thermocouples.
are.available.for.use.in.different.temperature.ranges..Two.
versions.of.EM.23.Thermocouple.modules.are.available,.one.
for.four.thermocouples.and.one.for.eight.thermocouples..Each.
version.is.compatible.with.J,.K,.T,.E,.R,.S,.or.N.thermocouples,.
but.the.thermocouples.used.with.a.specific.module.must.be.of.
the.same.type.
EM.23.RTD.module.provides.analog.inputs.for.resistance
temperature detectors (RTDs)..An.RTD.is.a.temperature.
sensor.made.from.a.metal,.such.as.platinum,.nickel,.or.copper,.
that.varies.in.resistance.in.a.predictable.manner.as.temperature.
varies..Two.versions.of.the.EM.23.RTD.module.are.available,.
one.with.two.analog.inputs.and.one.with.four.analog.inputs..
Either.version.can.be.used.with.a.variety.of.RTD.types,.but.the.
RTDs.used.with.a.specific.module.must.be.of.the.same.type.
A+ A- B+ B- C+ C- D+ D-
Configuration
M L+
Refer to the S7-200 Programmable
Controller System Manual for
+ Configuration DIP Switch Positions
-
24 VDC
SIMATIC
S7 - 200
SF/DIAG
CPU 224
RUN 00 01
AC/DC/RLY
STOP .0 .1 .2 .3 .4 .5 .6 .7 .0 .1
.0 .1 .2 .3 .4 .5 .6 .7 .0 .1 .2 .3 .4 .5
I0 I1
PORT
0
S7-200 PLC with EM 231 Expansion Module
69
A+ A- a+ a- B+ B- b+ b-
Configuration
M L+
Refer to the S7-200 Programmable
Controller System Manual for
+ Configuration DIP Switch Positions
-
24 VDC
EM 231 RTD module, 2 Input Version