Front-Panel Initialization; Battery Backup - Tektronix 7A42 Operator's Manual

Operating Instructions-7A42
k
L 2
TABLE 2-1 (CONT)
7A42 Self-Test Failure Messages
CH2,
second
column
(cont)
Trigger
(cont)
TRIGGER FUNCTION
(LED display)
Boolean
logic.
lndlcation
Some trigger
functions may not
be operational.
Repair before use.
severity
of failure;
usability
of instrument
Test
SWITCHING THRESHOLD
VOLTS and crt readout display
A THEN B
Indication
Avoid use of
A THEN B mode
Repair when
convenient.
Test
CH3,
second
column
Edge
detectors
Edge
detectors
Avoid use of
Edge-qualified
triggering mode
and external
clock. Repair
when convenient.
CH4,
second
column.
EXT
CLOCK
EXT
CLOCK
Avoid use of
external clock
Repair when
convenient.
FRONT-PANEL INITIALIZATION
While getting acquainted with the 7A42, it might be desirable to begin operation
with the front-panel controls set to a known state (initialized). The front panel will
initialize to the control settings listed in Table 2-2 and as shown in Figure 2-12. To
initialize the 7A42 front-panel control settings, see Exercise 1 in the Get-
Acquainted Exercises of this section.
BATTERY BACKUP
Upon completion of the self-test sequence, the 7A42 battery backup feature
restores the 7A42 front-panel control settings to the same settings that were
present when the power was turned off.