Added support for SR_CONF_REGULATION which returns value for CH1
Also VELLEMAN LABPS3005D (only device currently supported) sends single
'M' character in beginning of return value, which is specially discarded.
With this driver it is possible to set voltage target and current
limit. Also enabling and disabling the output is possible.
Analog output sends read back values from output. If output is
disabled analog outputs 0.00.
In protocol.c there is a g_usleep() call. This gives almost
every time enough time for PSU to parse and process input.
Multichannel devices aren't supported.
Uwe Hermann
Hannu Vuolasaho
Daniel Elstner