Communication with M-Bus
2CMC48001M0201 187 A43/A44
Revision: C User Manual
Value Information
block (VIB)
Data
Manufacturer
data header
(MDH)
The following table shows the structure of the Data Information Field
Extension (DIFE)
The following list explains the content of the DIFE:
• Unit is used for power and energy values show the type of power/energy.
It is also used to define the number of inputs/outputs and to specify sign
of offset when accessing event log data.
• Tariff is used for energy values to give tariff information.
• Storage number is set to 0 in values read to indicate momentary values.
Storage number bigger than 0 is used to indicate previously stored values,
i.e, values stored at a specific point of time in the past.
VIB follows a DIF or DIFE without extension bit. It contains one value
informa-tion field (VIF) and is in some cases expanded with up to 10 value
information field extensions (VIFE).
The following table shows the structure of the value informatiuon field (VIF):
Value information contains information about the value (unit, status, etc.,)
The extension bit is set when the next byte is a VIFE.
If VIF or VIFE = FFh the next VIFE is manufacturer specific. The manufacturer
specific VIFE has the same construction as a VIF. If the extension bit of the
man-ufacturer specific VIFE is set, and the VIFE is less than 1111 1000, the
next byte is a standard VIFE, otherwise it is the first data byte. If the extension
bit of the manufacturer specific VIFE is set and the VIFE is bigger than or equal
to 1111 1000, the next byte is an extension of manufacturer specific VIFE's.
The Data follows a VIF or a VIFE without the extension bit set.
The manufacturer data header (MDH) is either made up by the character 1Fh that
indicates that more data will follow in the next telegram, or by 0Fh indicating
the last telegram.
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