Table 3-1. Front Panel Controls and Indicators-continued

TM 11-6625-3024-14/EE641-AC-MMA-010/E154 SYSEX/TO 33AA50-5-1-1

Table 3-1. Front Panel Controls and Indicators (Continued)

Control/Indicator

Function

Selects all tracks at once to PATTERN write data.

ALL PAT.

The blue portion (PAT.) of WRITE DATA indicators

Switch (blue)

for all tracks will light.

ALL 1

Selects all tracks at once to logic 1 write data. The

Switch (yellow)

yellow portion (1) of the WRITE DATA indicators for

all tracks will light.

INSERT ERROR

Inserts error by inverting parity bit for one clock

Switch (red)

time each time switch is pressed. Button must be

pushed while data is being written to induce an

error in PAT. mode only.

READ DATA

Grid, 0 through 7, P and CLK

The returned READ DATA for tracks 0 through 7,

Test Jacks

Parity track, and Read Clock are available at the

test jacks. The GND test jack is used as return for

all read data test jacks.

PARITY ERRORS

SOFT ERROR

Displays all parity errors counted in the read mode.

Digital Display

HARD ERROR

Displays the errors detected by the Exerciser

Digital Display

central processor when REPEAT ON ERROR

mode is used. (The central processor commands

all errors to be evaluated three times. ) The error is

reported as a HARD ERROR if the error exists after

three evaluation cycles with REPEAT ON ERROR

function.

(Vertical Redundancy Check) indicates when any

VRC ERROR

parity error is detected. Indicator will remain lit

Indicator

until reset.

LRC ERROR

Indicates when any Longitudinal Redundancy

Indicator

Check (LRC) error is detected. Indicator will

remain lit until reset.

RESET

Resets the VRC ERROR and LRC ERROR indi-

Pushbutton Switch

caters, SOFT ERROR counter and display, and

HARD ERROR counter and display, when pressed.

3-8