7.2.5 Log channels
There are 32 logical log channels available, which can be freely configured. These
channels store all the parameters that the AD-VL 500 needs to record a value via the
Modbus. The following parameters can be configured per channel:
Parametername
Default value
Range
Unit
Slave address[N]
1
0 ... 247
Holding register[N]
0 ... 65535
Data type[N]
FPN (Single)
U08,
S08,
U16,
S16,
U32,
S32,
FPN
Log interval[N]
5
1 ... 65535
s
Log enable[N]
Nein
Nein, Ja
Label[N]
’Kanal N’
0 ... 20
Zeichen
Unit[N]
’ ?’
0 ... 10
Zeichen
[N] is the 1-based index of the channel [1..32].
Example: With the setting
Slave address
= ’
2
’,
Holding register
= ’
41120
’,
Data type
= ’
FPN(Single)
’,
Log interval
= ’
10
’, a floating point number from
the modbus slave with slave address 2 is stored in the log file every 10 seconds.
Choose a log interval that is as large as possible to keep file
sizes down. Large files have an unfavourable effect on time, data
transfer and later evaluation.
Basically, all holding registers that have an entry greater than zero are read perma-
nently. This means that these values can be shown on the display or the HTML page
without necessarily having to be logged.
Activation of the log function of the individual holding register itself is done with the
selector switch
log enable = yes
.
Floating point numbers (single or float) according to IEEE 754
have a size of 4 bytes, so 2 Modbus registers are read.
The AD-VL 500 only contains default values as analogue data logger. When connecting
additional Modbus slaves, the AD-VL 500 must always be set up for the application.
This can be done by the user himself or in consultation with the Adamczewski elektro-
nische Messtechnik GmbH . Ready-made configurations can be downloaded from the
manufacturer’s website.
The unit’s own data (measured values, counter readings) are
read on the virtual slave address 0 and are not communicated via
the physical RS-485 interface.
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