CARLO GAVAZZI VMU-C EM, Инструкция по эксплуатации

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VMU-C
VMU-C Instruction manual 27
 “
Enable Modbus TCP Mapping
”: check the relevant box to enable the selected
meter in the Modbus TCP map.
 “Modbus TCP address ”: set the relevant Modbus TCP address (1 to 247)

“Variables Available”:
check the variables that must be retransmitted among the
list of all the available ones.
A set of keys allow to help in the variable
selection: “All” key to select all the available
variables, “None” key to unselect all the variables, “Filter” key to enable/disable (toggle
button) the variables described in the above combo box. In the example picture above,
pressing “Filter” will enable/disable all the Reactive Power variables (system and single
phase var).
In case a variable is deleted or added in a second time, please refer to next paragraph.
Press “Save” key to store the modifications, “Back” to go back to the previous page
without saving.
3.1.6.3 Notes about Modbus TCP Mapping in VMU-C EM
The data format is IEEE754 (even if differently managed by the meter, e.g. INT 32) for all
the instantaneous variables; it is INT64 with 0,1 kWh (or m3) resolution for all the meters
or utility counters.
The web server and the Modbus TCP slave communication work at the same time over
the Ethernet port of VMU-C EM.
When the Modbus TCP map is created, the variable are listed following a predefined
order.
In case a variable is deleted in a second time, the relevant Modbus memory address will
be left empty. In this case the floating point value FFFF FFFFh (meaning “NaN”, “not a
number”) or the UINT64 value FFFF FFFF FFFF FFFFh can be read in this memory
address.
In case a variable is added in a second time, the relevant Modbus memory address will
be automatically assigned after the existing ones.
If variables are added and removed so many times to fill all the available addresses in
the map, a message will appear asking to reset and regenerate all the maps with the
relevant command (see above).