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= Key 1
= Key 2
= Key 3
= Maximum or consumption = Minimum or supply.
Ring buffer data format
Data sets can be saved in compressed or uncompressed
form. With the presettings, the data are saved com-
pressed.
The programming and reading out software
PSW503basic can read compressed data from ring buf-
fer only. Other applications can read data sets in uncom-
pressed form only.
An uncompressed data set consists of the type of measu-
red value, the date and the measured value. This value is
always given in Float format.
1)
r/w = read/write
2)
Measured values {float: Actual value[L1, L2, L3],
Mean value[L1, L2, L3]
, Minimum[L1, L2, L3], Maximum[L1, L2, L3]}
Changeover ring buffer
The changeover from compressed to uncompressed
storage of data is carried out via the serial interface. If
the Modbus RTU protocol is used, please use the
addresses
. If the Profibus DP protocol is used, please use
the
index
.
If data should be saved uncompressed within the ring
buffer, address
19010
dez (Index
11
) must be overwritten
by 2 Bytes of a content by choice.
If data should be saved uncompressed within the ring
buffer, address
19020
dez (Index
12
) must be overwritten
by 2 Bytes of a content by choice.
Type of measured value
The type of the measured value can be determined by the
addresses from the tables 1a and 1b. Example: If the type
is marked by the decimal number „1004“, this
corresponds to the current mean value in phase L2.
Date
In the part of the data set with the description „
Date“,
the date and time of the measurement are saved.
char: Year, Month, Day, Hour, Minute, Second
Diagr. Structure of „Date“
Meas. val. type Date Meas. value
2 Bytes
6 Byte 4 Byte (float)
Read ring buffer
If the data sets have been saved uncompressed, they can
be read via the serial interface with Modbus protocol.
To make this reading easy, there is a
ring buffer pointer
(4 Byte) available. This ring buffer pointer always points
to the beginning of a data set. One data set consists of 12
Bytes.
Attention!
If another way of compression is selected, the
total content of the ring buffer is
deleted
.
Table 1a, Measured value
Meas. val. in floating point form.
Description
Addr.(dez) r/w1)Type
Current
1000
r
Meas. val
2)
A
L1, L2, L3
1001
r
Actual value
in L2
1002
r
Actual value
in L3
1003
r
Mean value
in L1
1004
r
Mean value
in L2
..
..
..
Voltage N-L
1012
r
Meas. val.
2)
V L1, L2,
Voltage L-L
1024
r
Meas. val.
2)
V L1-L2, L2-L3,
Real power
1036
r
Meas. val.
2)
W Sign -=Supply.
..
..
..
..
.. ..
Extract from tab
le 1a
Diagr. Assign measured value type.
Type
Date
Meas. value
2 Bytes
6 Byte 4 Byte (float)
Ring buffer
Data set 1
Data set 2
Data set 3
.
.
.
Data set n
Data set n+1
.
.
Oldest data set in ring buffer
Ring buffer pointer = 0000.
Last saved data set
Next data set, that will be
saved
Diagr. Data sets in ring buffer.
Attention!
The inaccuracy of the compressed memory data
is max. ±0,4% rng.
