Louis Taber

US Patent:

44334249, Feb 21, 1984

Filed:

May 11, 1981

Appl. No.:

6/262719

Inventors:

Louis Taber - Tucson AZ
Don G. East - Tucson AZ

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04L 702

US Classification:

375106

Abstract:

A clocking system is disclosed for a multichannel data transmission system which includes a temporary storage medium, such as magnetic tape. The system is an improvement over prior art systems which utilize a separate phase locked loop clock correction circuit for each channel. The described system utilizes a single clock for the multiple channels which operates at a frequency F that is an integral multiple of the channel baud rate. Means are provided to continually monitor the phase error of each channel and a composite correction signal is derived and applied to the clock signal which is proportional to the average of the phase errors of the individual channels.