Figure 3-3. Start/Stop Time Waveforms.

11-5835-243-34/EE641-AA-MMl-010/E154

MTT/TO

31S3-4-110-1

Alternately depress STOP and RUN FORWARD to

ramp first crosses +3 percent level (fig. 3-3). Each

display signal.

major division on the scale equals 20 percent.

(7) Verify that start time (measured as in step

(5) Verify that start time is within 30 to 33 ms.

(4) is within 60 to 66 ms.

(6) Depress FAST switch on exerciser.

EL4RD046

Figure 3-3. Start/Stop Time Waveforms.

(3) Connect CH1 of oscilloscope to TP1 of

b. Stop Time.

control logic circuit card A4 and set oscilloscope to

(1) Set oscilloscope to trigger on the positive

trigger on the positive-going edge of the pulse.

edge of the external trigger signal at A5, TP3 when

Display successively on CH2 the signal at TP4,

RUN FORWARD switch on exerciser is depressed.

TP5, and TP6 of digital read/write circuit cards Al,

(2) Display the signal present at A5, TP5.

A2, A3 noting which positive signal transition is

Adjust signal amplitude or oscilloscope so that it is

most delayed from start of sweep. Connect CH2 to

five divisions peak-to-peak.

this most delayed point. Refer to table 3-1 for test

(3) Measure the period from start of sweep to

point/tape track number identification.

where ramp first crosses 97 percent level (fig. 3-3).

(4) Measure the period from start of sweep to

Each major division on the scale equals 20 percent.

center of jittered signal transition (fig. 3-4) and

(4) Verify that stop time is within 58 to 64 ms.

verify that static skew is 5.6 microseconds

(5) Set FAST switch off. Set exerciser for RUN

maximum.

FORWARD, WRITE, BLOCK MODE operation.

(5) Depress STOP and REWIND switches on

(6) Repeat step (3) and verify that stop time is

exerciser.

within 29 to 32 ms.

(6) When BOT status is reported, remove skew

(7) Depress REWIND switch on exerciser.

tape cartridge, replacing it with the write enabled

3-15. Skew Test

standard cartridge used in previous sections of this

procedure. Close and lock tape transport access

a. Static Skew and Dynamic Skew A.

door.

(1) On exerciser, set WRITE and FAST

(7) Set WRITE switch and WRITE DATA

switches off. Insert skew tape cartridge

ALL 1 switch on. Depress REWIND switch on

TW-433/UYH-5. Close and lock access door.

exerciser.

Depress REWIND switch.

(2) After BOT status is reported, depress RUN

(8) After BOT status is reported, depress RUN

FORWARD switch.

3-7