Balluff BVS Serial Command format

 

Balluff BVS used as a bar code reader

The Balluff BVS-ID-3-005-E is a vision sensor with barcode reader tools.  The sensor can be triggered using an RS-232 serial command.

Balluff BVS001R  BVS-ID-3-005-E  Vision sensor and barcode reader.

I had some trouble figuring out that the serial command and the ethernet command have slightly different syntax.

The RS-232 serial command to trigger the camera is:

TRIGGER<0x00>

  where <0x00> is a byte with the value of zero.

The response is:

<0x02>OK&ACK<0x0D><0x0A>        

  byte value 02 followed by ASCII ending with Carriage Return and Line Feed bytes 13 (0D) and 10 (0A)

When using ethernet the trigger command is:

TRIGGER

No Null byte is needed.

The response is:

OK&ACK<0x00>

The null byte is part of the response.

Why are these different?  I spent about 5 hours troubleshooting this.

Edit 20200121:

And get this, the PLC that needs to send the trigger command can't automatically send the <0x00> null byte at the end of the TRIGGER string.  The PLC's string and serial com library treat the <0x00> as the null termination character for the string.  So it doesn't send the the <0x00> byte.  We tried to concatenate a '$00' in structured text (which is the null byte <0x00>) and it just ignores it.  Ultimately Roger, the programmer of the PLC, had to overwrite the serial communication "Data to Send" register, from 7 to 8 bytes.   Sysmax studio may require the overwrite.