© Adolf Thies GmbH & Co. KG · Hauptstraße 76 · 37083 Göttingen · Germany
021821/08/21
Tel. +49 551 79001-0 · Fax +49 551 79001-65 · [email protected] ·
Page 48 of 102
Note on the micro USB slave interface
For communication via
micro
USB it is necessary to have an installed VCP driver (Virtual
COM Port) on the PC used. VCP drivers ensure that a
micro
USB device is available as an
additional COM port on the PC. The user software can then treat the
micro
USB device like a
standard COM port. The parameters (baud rate, data bits and parity) must correspond to the
setting of the
micro
USB slave interface of the Data logger.
The driver is available from FTDI (FT245R): http://www.ftdichip.com/
In addition, installation guides in English for different operating systems can be downloaded
there.
6.3 Data Line
The data is output in a line with a fixed telegram length. Each line starts with the time stamp,
followed by the measured values including status word. The separator between measured
value and status word is the semicolon, separator between the measured values and the
time stamp is the semicolon. The status word represents a 16-bit integer value without a sign
and is always output with 5 places. All data lines are concluded by “CR LF”. A dot is used as
a decimal separator. Incorrect values are identified by a status word unequal 0. The end of
the data output is identified with an end line with the command DS.
Note:
The time stamp of a data line refers to the end of the measurement.
The status word is bit coded, i.e. every single bit represents a particular status and/or error.
The following table shows the meaning of the individual bits.
Bit number Function
Description
Bit 0
Bit 1
ADC error
An error has occurred in the AD implementation.
Bit 2
ADC timeout
The AD implementation has not been concluded in the
predefined time.
Bit 3
Wire break
A cable break has been detected.
Bit 4
MAX
The channel value has exceeded the configured maximum
value.
Bit 5
MIN
The channel value has fallen short of the configured minimal
value.
Bit 6
Checksum
The checking of the checksum yielded an error.
Bit 7
Framing
The checking of the data frame yielded an error.
Bit 8
AV buffer low
The number of valid measured values in the average value
buffer is too low.
Bit 9
Linked channel
index
The channel index for a connected channel is incorrect.
Bit 10
Invalid character
An invalid character was detected.
Bit 11
String too long
The received/decoded string is too long.
Bit 12
Maths error
The calculation being used as the basis caused a mathematical
error (e.g. an attempted division by 0)
Bit 13
MODBUS
A MODBUS exception has been received.
Bit 14
Archiving off
The channel is not archived.
Bit 15
Channel off
The channel is switched off.
Table 7: Status word
