Siemens LOGO! CMR2040 Operating Instructions Manual page 48

Operation: Access to BM
4.2 Reading and writing values
For reasons of security, setting or reading of current values of the function blocks of the BM
(e.g. counters) is possible only via their address in the BM variables memory.
All components of the LOGO! switching program must therefore initially be transferred to the
BM-internal variables memory using the "LOGO! Soft Comfort" program. Only then are the
components visible with their start addresses and length (type) for the CMR in the BM
variables memory.
Data types and range of values when reading and writing
To set individual bits, the data types available must be used.
LOGO! CMR and LOGO! BM interpret all values of the data types BYTE, WORD and
DWORD as being signed.
Remember this when transferring values using SMS messages.
Data type
BIT
BYTE
WORD
DWORD
Reading and writing values in the variables memory (VM) of the LOGO!! BM using SMS messages
With the LOGO! CMR, values can be written to and read from the variables memory (VM) of
a LOGO! BM using SMS messages.
The parameters to be specified in SMS commands are the address and type (<address>,
<data type>, refer to the section SMS commands (Page 166).
In the WBM of the LOGO! CMR, a limit this or a threshold value for a value from the LOGO!
8 can be specified on the "Monitoring" > "Events" page. If the threshold of the value in the
LOGO! 8 is exceeded or fallen below, the sending of an SMS message to one or more
recipients can, for example, be configured.
Note the signed interpretation of the values also in the following applications:
● Setting threshold/limit values for values in the LOGO! BM via the WBM of the
LOGO! CMR
● Display of values in the LOGO! BM via the WBM of the LOGO! CMR
● Reading/writing values in the LOGO! BM using SMS messages with the LOGO! CMR
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Length in the variables
memory:
1 bit
1 byte
2 bytes
4 bytes
Range of values
0, 1
-128 ... 127
-32 768 ... 32 767
-2 147 483 648 ... 2 147 483 647
LOGO! CMR2020,
Operating Instructions, 10/2016, C79000-G8976-C356-03
LOGO! CMR2040