Library /sys$common/syshlp/ncphelp.hlb SET, LINE, SCHEDULING TIMER milliseconds  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Applies only to DDCMP CONTROL lines.  Specifies the number of
 milliseconds between re-calculation of tributary polling priorities.
 The number of milliseconds must be a decimal integer up to a maximum
 of 65,535.  The default is 50.