Browse Prior Art Database

Magnetic Tape Unit Failure Detection

IP.com Disclosure Number: IPCOM000075919D
Original Publication Date: 1971-Dec-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Ashbee, WH: AUTHOR [+3]

Abstract

This failure detection apparatus stops operation of a magnetic tape unit (MTU) and sets latches to subsequently provide failure information, whenever (1) read status is set and write head current is sensed, (2) read status is set and erase head current is sensed, or (3) write status is set and the absence of erase head current is sensed.

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Magnetic Tape Unit Failure Detection

This failure detection apparatus stops operation of a magnetic tape unit (MTU) and sets latches to subsequently provide failure information, whenever (1) read status is set and write head current is sensed, (2) read status is set and erase head current is sensed, or (3) write status is set and the absence of erase head current is sensed.

A magnetic tape unit, such as shown in Fig. 1, includes a tape processing station 1 having three spaced heads. The tape, when moving in a forward direction, first encounters the erase head, then the multigap write head and then the multigap read head. Fig. 2 shows the proper condition for erase head and write head currents for the read and write status of the MTU.

In Fig. 3 a single erase-head gap coil and a single write-head gap coil are shown. One coil is provided for each gap of these multigap heads. The circuit associated with the erase head coil provides an active signal on conductor 2 whenever erase head current is not present, and an active signal on conductor 3 whenever erase head current is present. The circuit associated with the write head coil provides an active signal on conductor 4 whenever write current is possible.

AND gate 5 provides an active signal on conductor 6 when the MTU is set to write status and a failure is indicated by the lack of erase head current. AND gate 7 provides an active signal on conductor 8 when the MTU is set to read status and a failure is indicated by...