Tape speed monitor

Claim 2

In a magnetic tape recording unit having write apparatus including a write-head for writing information on a magnetic tape, having read apparatus including a read-head for reading information from the magnetic tape, and having transport means for transporting the magnetic tape from the write-head toward the read-head at speeds which may vary, a tape speed monitor comprising, a counter for counting timing pulses, starting circuit means for starting the count in said counter when data is written on the magnetic tape, output means, responsive to a predetermined count in said counter when said data is read from the magnetic tape, for generating an alarm signal signifying a tape speed error.

Claim 3

The tape speed monitor of claim 1 wherein said output means includes a decoder, enabled by the reading of said data from the magnetic tape, responsive to a predetermined count in said counter for indicating that the tape speed is above a predetermined limit.

Claim 4

The tape speed monitor of claim 1 further including stopping circuit means for stopping the counting of said counter when said data is read from the magnetic tape and further including a decoder responsive to a predetermined count in said counter for signifying that the tape speed is below a predetermined limit.

Claim 5

The tape speed monitor of claim 1 further including stopping circuit means for stopping the counting of said counter when said data is read from the magnetic tape and wherein said output means further includes a first decoder, enabled by the reading of said data from said magnetic tape, responsive to a first predetermined count in said counter for indicating that the tape speed is above a predetermined first limit, and further includes a second decoder responsive to a second predetermined count in said counter for signifying that the tape speed is below a predetermined second limit.

Claim 6

A magnetic tape speed monitor for use with a magnetic tape unit which has a write-head and write control apparatus which signals with a signal DA when data is first written on a magnetic tape, has a read-head and read apparatus which signals with a signal RC when said data is first read from the magnetic tape and has tape transport apparatus which transports the magnetic tape in the direction from the write-head toward the read-head at speeds which may vary, said tape speed monitor comprising, a source of timing pulses, a digital counter for counting the timing pulses, starting circuit means for starting the counter counting said timing pulses in response to the DA signal, stopping circuit means for stopping said counter from counting in response to the RC signal, and output means responsive to a predetermined count in said counter for generating an alarm signal signifying that the tape speed varies from a predetermined limit.

Claim 7

A magnetic tape speed monitor for use with a magnetic tape unit which has a write-head and write control apparatus which signals with a signal DA when data is first written on a magnetic tape, has a read-head and read apparatus which signals with a signal RC when said data is first read from the magnetic tape and has tape transport apparatus which transports the magnetic tape in the direction from the write-head toward the read-head at speeds which may vary, said tape speed monitor comprising, a source of timing pulses, a digital counter for counting the timing pulses, starting circuit means for starting the counter counting said timing pulses in response to the DA signal, stopping circuit means for stopping said counter from counting in response to the RC signal, and output means responsive to a predetermined count in said counter for generating an alarm signal signifying that the tape speed varies from a predetermined limit.

Claim 8

The tape speed monitor of claim 5 wherein said output means includes a decoder, enabled by the RC signal, responsive to a predetermined count in said counter for indicating that the tapE speed exceeds a predetermined limit.

Claim 9

The tape speed monitor of claim 5 wherein said output means includes means responsive to a predetermined count in said counter for signifying when said tape speed is below a predetermined limit.

Claim 10

The tape speed monitor of claim 5 wherein said output means further includes a first decoder responsive to a predetermined first count in said counter when enabled by said signal RC for indicating that the tape speed exceeds a predetermined first limit and a second decoder responsive to a predetermined second count, greater than said first count, in said counter for indicating that the tape speed is below a predetermined second limit, less than said first limit.

Claim 11

In a system having first and second magnetic tape units, each including write apparatus for writing information on a magnetic tape, read apparatus for reading information from the magnetic tape, and transport means for transporting the magnetic tape in the direction from the write apparatus toward the read apparatus, a control system comprising, first and second tape speed monitors associated with said first and second tape units, respectively, for generating first and second alarm signals, respectively, each tape speed monitor including a counter for counting timing pulses, including starting circuit means for initiating counting in said counter when data is first written in the associated magnetic tape unit, including output means responsive to a predetermined count in said counter when said data is read for generating the alarm signal signifying a tape speed error in the associated tape unit, first and second control networks for enabling the first and second tape units, respectively, and enabling the first and second tape speed monitors, respectively, said first and second control networks responsive to said second and first alarm signals, respectively, for enabling a tape unit and tape speed monitor which is not producing an alarm signal.

Claim 12

In a system having first and second magnetic tape units, each including write apparatus for writing information on a magnetic tape, read apparatus for reading information from the magnetic tape, and transport means for transporting the magnetic tape in the direction from the write apparatus toward the read apparatus, a control system comprising, first and second tape speed monitors associated with said first and second tape units, respectively, for generating first and second alarm signals, respectively, each tape speed monitor including a counter for counting timing pulses, including starting circuit means for initiating counting in said counter when data is first written in the associated magnetic tape unit, including output means responsive to a predetermined count in said counter when said data is read for generating the alarm signal signifying a tape speed error in the associated tape unit, first and second control networks for enabling the first and second tape units, respectively, and enabling the first and second tape speed monitors, respectively, said first and second control networks responsive to said second and first alarm signals, respectively, for enabling a tape unit and tape speed monitor which is not producing an alarm signal.

Claim 13

The control system of claim 9 wherein said output means for each of said tape speed monitors includes a decoder responsive to a predetermined count in said counter when enabled by the reading of said data for indicating that the tape speed is above a predetermined limit.

Claim 14

The control system of claim 9 wherein each of said tape speed monitors further includes stopping circuit means for stopping the count of said counter when said data is read from the magnetic tape and wherein the output means for each of said tape speed monitors further includes a decoder responsive to a predetermined count in said counter for signifying that the tape speed is below a predetermined limit.

Claim 15

The control system of claim 9 wherein each of said tape speed monitors further includes stopping circuit means for stopping the count of said counter when said data is read from the magnetic tape and wherein said output means for each of said tape speed monitors further includes a first decoder responsive to a predetermined first count in said counter when enabled by the reading of said data for indicating that the tape speed is above a predetermined first limit, and further includes a second decoder responsive to a predetermined second count in said counter signifying that the tape speed is below a predetermined second limit.

Claim 16

A magnetic tape speed monitor for monitoring the speed of magnetic tape comprising, a source of timing pulses, a digital counter for counting said timing pulses, starting circuit means for starting said counter counting said timing pulses when data is first written on the magnetic tape, stopping circuit means for stopping said counter from counting when said data is first read from the magnetic tape, and output means responsive to a predetermined count in said counter for generating an alarm signal signifying a tape speed error.

Claim 17

A magnetic tape speed monitor for monitoring the speed of magnetic tape comprising, a source of timing pulses, a digital counter for counting said timing pulses, starting circuit means for starting said counter counting said timing pulses when data is first written on the magnetic tape, stopping circuit means for stopping said counter from counting when said data is first read from the magnetic tape, and output means responsive to a predetermined count in said counter for generating an alarm signal signifying a tape speed error.

Claim 18

The tape speed monitor of claim 13 wherein said output means includes a decoder enabled by the first reading of said data, said decoder responsiVe to a predetermined count in said counter for indicating that the tape speed exceeds a predetermined limit.

Claim 19

The tape speed monitor of claim 13 wherein said output means includes a decoder responsive to a predetermined count in said counter for signifying when the tape speed is below a predetermined limit.

Claim 20

A magnetic tape speed monitor for use with a magnetic tape recording unit which has a write-head and write control apparatus for signaling with a signal DA when data is first written on a magnetic tape, has a read-head and read apparatus for signaling with a signal RC when said data is first read from the magnetic tape, and has a tape transport for transporting the magnetic tape in a direction from the write-head toward the read-head at speeds which may vary, said tape speed monitor comprising, a source of rectangular wave timing pulses, a binary digital counter for counting said timing pulses, said counter including means for being cleared and means providing parallel outputs representing predetermined digital counts stored by said counter, starting circuit means including a first flip-flop latched in response to said signal DA and including a gate which is enabled by said first flip-flop when latched to pass said timing pulses to said counter, stopping circuit means, including a second flip-flop latched in response to said signal RC, said second flip-flop operative to clear said first flip-flop and disable said gate so as to inhibit further timing pulses input to said counter and to clear said counter, a first decoder operative to receive a first output from said counter for detecting a first predetermined count when enabled by said signal RC to signal that the tape speed exceeds a predetermined first limit, a second decoder connected to receive a second output from said counter for detecting a second predetermined count, if said counter is not first cleared by the operation of said second flip-flop, to signal that the tape speed is below a predetermined second limit, logical combining means for combining the outputs of said first and second decoders to signal an alarm whenever said tape speed is outside a range defined by said predetermined first and second limits.

Claim 21

A magnetic tape speed monitor for use with a magnetic tape recording unit which has a write-head and write control apparatus for signaling with a signal DA when data is first written on a magnetic tape, has a read-head and read apparatus for signaling with a signal RC when said data is first read from the magnetic tape, and has a tape transport for transporting the magnetic tape in a direction from the write-head toward the read-head at speeds which may vary, said tape speed monitor comprising, a source of rectangular wave timing pulses, a binary digital counter for counting said timing pulses, said counter including means for being cleared and means providing parallel outputs representing predetermined digital counts stored by said counter, starting circuit means including a first flip-flop latched in response to said signal DA and including a gate which is enabled by said first flip-flop when latched to pass said timing pulses to said counter, stopping circuit means, including a second flip-flop latched in response to said signal RC, said second flip-flop operative to clear said first flip-flop and disable said gate so as to inhibit further timing pulses input to said counter and to clear said counter, a first decoder operative to receive a first output from said counter for detecting a first predetermined count when enabled by said signal RC to signal that the tape speed exceeds a predetermined first limit, a second decoder connected to receive a second output from said counter for detecting a second predetermined count, if said counter is not first cleared by the operation of said second flip-flop, to signal that the tape speed is below a predetermined second limit, logical combining means for combining the outputs of said first and second decoders to signal an alarm whenever said tape speed is outside a range defined by said predetermined first and second limits.