The Level I logger and the Level II logger are great tools for logging events in a VSCP based system. Useful also for debugging etc. Another method is to use the execute external program action and execute a script and write to a file there. We have seen this method being used in other howtos. Also while running a JavaScript or a Lua script files can be written.
But…
file writing is also available as an action. It is documented here. This action allows writing or appending a string with output to a named file that is created if it does not exist. With the VSCP escapes a lot of dynamic information can go into this file.
Suppose that we want to log events of a certain type to a file, here CLASS1.DATA, Type=2 A/D values form a specific device. We then write a decision matrix (DM) row
<row enable="true" groupid="" > <comment> Collect A/D values from node X </comment> <mask priority="0" class="0xFFFF" type="0xFFFF" GUID="FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF:FF" /> <filter priority="0" class="15" type="2" GUID="00:01:02:03:04:05:06:07:08:09:0A:0B:0C:0D:0E:0F" /> <action>0x70</action> <param> /tmp/addata;1;%isoboth: %measurement.string %lf </param> </row>
will generate output content like this
With the other VSCP escapes and literals you have many options to generate meaningful output.