ABB A43

Communication with Modbus
A43/A44 120 2CMC48001M0201
User Manual Revision: C
Entry number
The Entry number register is used to specify an entry number to start reading
register
from. When a value is written to the Entry number register the Data block is
loaded with values for that entry number.
Subsequent writes to Get next entry register will update the Entry number register
(increment or decrement depending on direction in the Direction register), as well
as loading new values to the Data block.
The default value of Entry number register after a restart is 0.
Date/Time
The Date/Time register is used to specify a date and time to start reading from.
register
When a value is written to the Date/Time register the Data block is loaded with
values for that date and time. The Entry number register is also automatically
updated, to reflect which entry number the values for this date and time has.
If there is no entry for the date and time chosen, and the reading direction is set to
backward, the nearest older entry will be loaded into the Data block. If the reading
direction is instead forward, the nearest newer entry will be loaded.
Subsequent writes to Get next entry register will load new data into the Data
block, in the order indicated by the Direction register. The Entry number register
will also be automatically updated (incremented or decremented depending on the
direction in the Direction register).
Direction register The Direction register is used to control the direction in time in which the entries are
read. Possible values are shown in the table below:
Value
Description
0
Backwards, i.e. from recent entries towards older entries
1
Forward, i.e. from old entries towards recent entries
Data block
registers
The default value of Entry number register after a restart is 0, i.e. backwards.
There are a number of standard data items that are used in the same way when
reading out any type of historical data. These are represented by registers in the Data
block, separately mapped for each functionality, but with the same names.
The following table describes the common Data block registers:
Function
Size
Description
Data type
Read
/write
Timestamp
3
The date and time on which the value was
Date/Time
R/W
stored
Quantity
3
OBIS code for the quantity concerned
6 byte
R/W
sequence