CDCHKON

 Function
  Turn on carrier detect checking.

 Syntax
  CDCHKON   No arguments are required

 Remarks
  PCBoard has built in automatic carrier detecting.  What this means is
  that if someone should hangup unexpectedly, PCBoard will detect it, log
  it to the callers log, and recycle back to the call waiting screen.  Some
  applications require the ability to turn this off; for example, a
    callback verification PPE needs to hangup on the caller and then do
  more processing.  Normally, PCBoard would just recycle at that point.
  So, just before you start a section of code that should continue
  regardless of the existence of a caller online, you should issue a
  CDCHKOFF statement.  It will turn off the automatic carrier checking.
  When you've finished the block where carrier checking has been
  disabled, issue the CDCHKON statement to turn it back on.

 Examples
  CDCHKOFF
  DTROFF
  DELAY 18
  DTRON
  SENDMODEM "ATDT1800DATAFON" ' Please don't call this number! :)
  WAITFOR "CONNECT",60
  CDCHKON