7-12
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
The following additional operating mode switch selections
are
possible
with
analog
module 464–8MA21:
With this function, you can obtain a characteristic linearization of the ther-
mocouples of type J, K, and L.
With module 464–8MA21, the linearization must always be activated to-
gether with the corresponding compensation of the reference point tempera-
ture.
Thermocouples:
Type J:
– 200
_
C ... + 200
_
C
Type K:
– 200
_
C ... + 1369
_
C
Type L:
– 199
_
C ... + 900
_
C
(in steps of 1
_
C in each case).
For the thermocouples of type J, K, and L, you can compensate for the tem-
perature of the reference point using a compensating box (see Figure 7-1).
It is also possible to move the reference point to the front of the module by
activating the “temperature compensation” function. When thermocouples
are directly connected, an internal circuit on the module causes the digital
value “0” to be displayed independently of the temperature of the terminal
when the temperature at the measuring junction is 0
_
C (32
_
F). To accom-
plish this, connect the terminals of the sensors directly to the module (i.e.,
without a copper extension cable).
Table 7-2
Settings for the Operating Mode Switch for Analog Input Module 464–8MA21
Function
Setting for Operating Mode Switch
Power Supply Fre-
quency
50 Hz
8
7
6
5
4
3
2
1
60 Hz
8
7
6
5
4
3
2
1
Operation
1 Channel
(Ch 0)
8
7
6
5
4
3
2
1
2 Channels
(Ch 0 and Ch 1)
8
7
6
5
4
3
2
1
4 Channels
(Ch 0 to 3)
8
7
6
5
4
3
2
1
Analog Value Processing
