There is not, but you can add one. The EBB has four three pin “servo outputs” available. The lowest of them (B1) is used for the pen lift servo. The other three (B0, B2, B3) are available for your use.
What you will need to do is to modify your software to add the command to turn the output on or off at the same time as you raise or lower the pen. If you’re using the standard Inkscape-based software, then you’ll want to open up and edit the script called “ebb_motion.py” in your Inkscape extensions directory. In that file, look for the sendPenUp and sendPenDown command definitions. There, you can add another line to send the I/O pin on or off command. Depending on what you’re actually doing, you may prefer to replace the pen up/down movements with just the pin on/off commands.
You might want to look at the “sendDisableMotors” command definition to see how we set up a one-liner command with no variables, as
ebb_serial.command( portName, 'EM,0,0r').
For the actual command to send, look at the PO command in the EBB command set documentation:
You may also want to refer to this discussion about adding a laser control: http://forum.evilmadscientist.com/discussion/comment/1992