I’ve been toying with the VelBus library for C#. After a while got it to do what I wanted, but the response from the RS232 module is not quite what I expect. When the device is connected to the bus I get 2 messages back, namely ‘receive ready’ and ‘bus active’, which makes sense (BTW, the user manual is incorrect as it says COMMAND_BUS_OFF = H’0A’ while it should be COMMAND_BUS_ACTIVE = H’0A’).
When I disconnect the device from the bus, I get no response at all. Should it say ‘COMMAND_BUS_OFF (H’09’) ?
While we’re at it… I’m wondering why you add a checksum to the command, while the CAN controller actually does it’s own CRC ?
Is this a left-over from early prototypes ?