Siemens S7-1200 Operating Instructions Manual page 84

Configuration and operation
4.15 STEP 7 configuration of individual parameters
Configuration of the limit value
The value to be configured as a whole decimal number therefore depends on the value
range of the PLC tags and the raw value of the analog module:
Division
Overflow
Overrange
Nominal range
(unipolar / life zero)
Nominal range (bipo-
lar)
Underrange
(unipolar / life zero)
Underrange (bipolar)
Undershoot / wire
break
* The raw values of the measured values relate to the values of 16-bit or 32-bit PLC tags.
Note
Evaluation of the value even when the option is disabled
If you enable one or both options and configure a value and then disable the option later, the
grayed out value is nevertheless evaluated.
To disable the two options, delete the previously configured values limit values from the input
boxes and then disable the relevant option.
Recommendation for quickly fluctuating analog values:
If the analog value fluctuates quickly, it may be useful to smooth the analog value first if limit
values are configured. If the analog value fluctuates close to a limit value for a longer period
of time, with a smoothed value you avoid a status change each time the value exceeds/falls
below the limit value and so triggers a transfer.
84
Raw value of the of PLC tags *
Decimal
16 bits 32 bits
32767 2147483647
32511 2130769779
... ...
27649 1812067105
27648 1811994624
... ...
0 0
27648 1811994624
... ...
0 0
... ...
-27648 -1811994625
-1 -1
... ...
-4864 -318729855
-27649 -1812067105
... ...
-32512 -2130769779
-32768 −2147483648
Module output [mA]
Hexadeci- 0 - 20
mal
(unipolar)
16 bits
7FFF > 23.515
7EFF 23.515
... ...
6C01 20.001
6C00 20
... ...
0000 0
6C00
...
0000
....
9400
FFFF -0.001
... ...
ED00 -3.518
93FF
...
8100
8000 < -3.518
Operating Instructions, 01/2015, C79000-G8976-C381-01
-20 - +20 4 - 20
(bipolar) (life zero)
> 23.515 > 22.810
23.515 22.810
... ...
20.001 20.001
20
...
4
20
...
0
...
-20
3.999
...
1.185
-20.001
...
-23.516
< 1.185
CP 1243-7 LTE
Measuring
range [%]
> 117.593
117.593
...
100.004
100
...
0
100
...
0
...
-100
-0.004
...
-17.59
-100.004
...
-117.593
< -17.593