User manual

8 LogGraph
DE Dostmann Electronic GmbH
Some functions can be tested using the additional program included in Windows
accessories "Hyper-terminal". These include the following functions:
"* IDN? "- gives a string with the IDs of the logger,
"* TST? - gives "0" if the logger is available, "-1" in case of communication problems
or
"* RST" - performs a soft reset of the logger.
In addition, many other commands are used in conjunction with certain parameters
to exchange data with the logger. Their explanation is not part of this documentation,
and would fill many more pages - this remark only completes the information
previously provided. Currently, there are no plans to disclose the commands and the
protocols hidden behind them.
The logger provides access to many internal parameters via a direct addressing of
the appropriate memory cell and reading of the data stored therein. Conversely, the
parameters may similarly be addressed and overwritten by the PC.
Besides the data transmitted, a checksum confirming the safety of the data
transmitted is also transmitted with each communication. The protocol itself is not
currently disclosed.
When downloading (reading out) the recorded data, a protocol encrypting the
transmission of a record in blocks of 5 bytes each (mode Penta) is used. During the
readout, all existing records are transmitted in one go as dump. The dump starts with
a header that contains the record number. Next come all the records. A checksum
also follows at the end of the entire transmission. This procedure is not currently
disclosed. Once launched, a dump can still be interrupted by the PC, however the
data are preserved in the logger.
In general, during the readout of records, no data is deleted from the logger, so that
the readout process can be repeated as often as you wish, as long as the records
have not been replaced by a newly launched record.