ABB A43

Communication with Modbus
A43/A44 122 2CMC48001M0201
User Manual Revision: C
Date and time The same date and time format is used wherever a date and time occurs in the
format registers, e.g. the Date/Time register in the Header or a timestamp in the Data
block. The following table shows the structure of date and time in the mapping:
Byte
Description
Comment on byte order
number
0
Year
Most significant byte of lowest register
1
Month
Least significant byte of lowest register
2
Day
...
3
Hour
...
4
Minute
...
5
Second
Least significant byte of highest register
Response times The Headers for reading out historical values include one or more of the registers
Entry number, Date/Time, Direction and Get next entry for controlling the readout.
When writing to any of the registers Entry number, Date/Time or Direction a
new search is started in the persistent storage, which can take a long time
depending on how old the entry searched for is. The response from Modbus is
given after the search is finished, i.e. when the requested entry has been found.
Recent entries are found fast, whereas finding the oldest can take seconds or
even up to about a minute if there are many thousands of newer values. It is
therefore preferable to start reading from a recent entry number or date/time
and then go backwards in time.
Writing to the Get next entry register continues the ongoing search
and consequently goes fast.
9.5.1 Quantity identifiers
The quantities stored in Previous values, Demand and Load profile are
identified by OBIS codes. The OBIS code is a 6 byte identifier. The tables
below list the OBIS codes for all quantities possible to configure.
Total energies The following table lists the OBIS codes for total energies:
Quantity
OBIS code
Active energy import total
1.0.1.8.0.255
Active energy export total
1.0.2.8.0.255
Active energy net total
1.0.16.8.0.255
Reactive energy import total
1.0.3.8.0.255