Library /sys$common/syshlp/ncphelp.hlb SET, CIRCUIT, INACTIVE INCREMENT increment  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Applies to DDCMP CONTROL circuits. This parameter indicates the
 increment value added to the INACTIVE tributary priority each
 time the scheduling timer expires. Increment must be a decimal
 integer from 0 to 255.  The default is 64.