E-T-A ControlPlex CPC20, User Manual

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9.2.7 »History« bar chart of circuit protector
The bar chart of a circuit protector contains 400 data sets with
the measuring values of load voltage (Uload) and load current
(Iload). The measuring values are saved as 8 bit values, i.e. a
total of 800 data bytes.
The measuring values are permanently saved in the circuit
protector with a frequency of 100 Hz. Recording is stopped
with disconnection of the load through short circuit, overload
or excess temperature (trip). The bar chart will then contain the
measuring values of the last 4 seconds. If for example the trip
time at overload is parameterised to be 3 seconds, the measuring
values will be saved 1 second before and 3 seconds after
overload detection of the circuit protector. As the data quantity
is too big for a non-cyclical query, the entire bar chart has to be
read with the four indices:
They are read with COM = 1...2, channel = 1...32 and index
7...10. Measuring values 1..200 are picked up with index 7, the
measuring values 201...400 with index 8, the measuring values
401..600 with index 9 and the measuring values 601..800 with
index 10. All parameters with possible conditions are described
in the following table.
byte type range description
load voltage 1 0 byte 0…255 The load voltage is calculated as follows:
value (148) * 0.2 = 24.864 Volt
load current 1 1 byte 0…255 The load current is calculated as follows:
(128 - value (80)) * 0.1639 = 7.107 Volt
load voltage 2 2 byte 0…255 The load voltage is calculated as follows:
value (148) * 0.2 = 24.864 Volt
load current 2 3 byte 0…255 The load current is calculated as follows:
(128 - value (80)) * 0.1639 = 7.107 Volt
... 4…197 byte 0…255
load voltage 200 198 byte 0…255 The load voltage is calculated as follows:
value (148) * 0.2 = 24.864 Volt
load current 200 199 byte 0…255 The load current is calculated as follows:
(128 - value (80)) * 0.1639 = 7.107 Volt
fig. 34: Bar chart