Siemens simatic et200sp - Page 41

Reading and processing measured values
6.3 Reading measured values from user data cyclically
Analog input module AI Energy Meter 480VAC ST (6ES7134-6PA20-0BD0)
Manual, 12/2015, A5E36061895-AA
41
Example
The user data variant 254 (FE
H
) "Total power L1L2L3" is configured on the AI Energy Meter
480VAC ST. The measured value for "Current L1" should be read.
Table 6- 1 Total power L1L2L3
Byte
Allocation
Data type
Unit
Value range
Measured
value ID
0
User data variant
BYTE
-
254 (FE
H
)
-
1 Quality information = QQ
1
I
3
U
3
I
2
U
2
I
1
U
1
BYTE Bit string qq xx xx xx -
2 ... 3
Current L1
UINT
1 mA
0 … 65535
66007
4 ... 5 Current L2 UINT 1 mA 0 … 65535 66008
6 ... 7
Current L3
UINT
1 mA
0 … 65535
66009
:
:
:
:
:
:
24
Scaling current L1
USINT
-
0 ... 255
-
25
Scaling current L2
USINT
-
0 ... 255
-
26
Scaling current L3
USINT
-
0 ... 255
-
:
:
:
:
:
:
31
Scaling total reactive energy L1L2L3
USINT
-
0 ... 255
-
In the user data variant FE
H
(254) the measured value for the current L1 is stored in Byte 2 +
3. The current is supplied by the module as a 16-bit-fixed-point number in the value range
from 0 to 65535 in the unit 1 mA. In addition the scaling factor for the current L1 has to be
considered additionally. The module supplies the related scaling factor in Byte 24.
The actual value for current L1 is calculated as follows:
Actual value for current L1 = Current L1 x 10
Scaling current L1
See also
Basics for reading measured values (Page 35)