Specifications

S7-200 Programmable Controller System Manual
430
EM 231 RTD Module
The EM 231 RTD module provides a convenient interface for the S7-200 family to several different
RTDs. It also allows the S7-200 to measure three different resistance ranges. Both RTDs
attached to the module must be of the same type.
Configuring the EM 231 RTD Module
DIP switches enable y ou to select RTD type, wiring
configuration, temperature scale, and burnout
direction. The DIP switches are located on the
bottom of the module as shown in this figure. For
the DIP switch settings to take effect, you need to
power cycle the PLC and/or the user 24V power
supply.
Select RTD type by setting DIP switches 1, 2, 3, 4,
a
n
d
5
t
o
c
o
r
r
e
s
p
o
n
d
t
o
t
h
e
R
T
D
a
s
s
h
o
w
n
i
n
T
a
b
l
e
↑1--On
↓0--Off
Con
f
iguration
12345678
an
d
5
t
o correspon
d
t
o
t
h
e
R
T
D
as s
h
own
i
n
T
a
b
l
e
A-31. Refer to Table A-32 for other DIP switch
settings.
Figure A-24 DIP Switches for the EM 231
RTD Module
Table A-31 Selecting the RTD Type: DIP Switches 1 to 5
RTD Type and
Alpha
1
SW1 SW2 SW3 SW4 SW5 RTD Type and
Alpha
1
SW1 SW2 SW3 SW4 SW5
100Ω Pt 0.003850
(Default)
0 0 0 0 0 100Ω Pt 0.003902 1 0 0 0 0
200Ω Pt 0.003850 0 0 0 0 1 200Ω Pt 0.003902 1 0 0 0 1
500Ω Pt 0.003850 0 0 0 1 0 500Ω Pt 0.003902 1 0 0 1 0
1000Ω Pt
0.003850
0 0 0 1 1 1000Ω Pt
0.003902
1 0 0 1 1
100Ω Pt 0.003920 0 0 1 0 0 SPARE 1 0 1 0 0
200Ω Pt 0.003920 0 0 1 0 1 100Ω Ni 0.00672 1 0 1 0 1
500Ω Pt 0.003920 0 0 1 1 0 120Ω Ni 0.00672 1 0 1 1 0
1000Ω Pt
0.003920
0 0 1 1 1 1000Ω Ni 0.00672 1 0 1 1 1
100Ω Pt
0.00385055
0 1 0 0 0 100Ω Ni 0.006178 1 1 0 0 0
200Ω Pt
0.00385055
0 1 0 0 1 120Ω Ni 0.006178 1 1 0 0 1
500Ω Pt
0.00385055
0 1 0 1 0 1000Ω Ni
0.006178
1 1 0 1 0
1000Ω Pt
0.00385055
0 1 0 1 1 10000Ω Pt
0.003850
1 1 0 1 1
100Ω Pt 0.003916 0 1 1 0 0 10Ω Cu 0.004270 1 1 1 0 0
200Ω Pt 0.003916 0 1 1 0 1 150Ω FS
Resistance
1 1 1 0 1
500Ω Pt 0.003916 0 1 1 1 0 300Ω FS
Resistance
1 1 1 1 0
1000Ω Pt
0.003916
0 1 1 1 1 600Ω FS
Resistance
1 1 1 1 1
1
All RTDs represent 0° C. at the listed resi stance except for Cu 10 ohm. Cu 10 ohm is 25° C. at 10 ohm and 0° C. at 9.035 ohm.