An XKL monitor can stay up longer than a standard DEC or PANDA monitor.  However, there is no way for a program to detect this with the TIME% JSYS.  XKL defined a magic value to put into AC1 that is looked for and, if it is not there, the call is failed with a TIMEX3 error.

Does anybody either know the definition of TIMEX3 or where I could get it?  It's not in the PANDA MONSYM.