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

 Applies only to DDCMP CONTROL lines. Specifies the minimum number of
 milliseconds to delay between polls.  This timer limits the effect of
 a very fast control station to slower tributaries.  The milliseconds
 value must be a decimal integer up to a maximum of 65,535.  If not
 set, there is no delay.