7A42 Operator
Messages
Code
Mnemonic
Description and Corrective Action
1
OVERLOAD
A
channel input is
overloaded. Remove the overvoltage
and
unground
the
channels to continue operation.
2
OFFSET ACQ
A
key
was
pressed while Probe Offset acquisition was
in progress.
Push PROBE OFFSET
once
to lock in
acquired
value, or
twice
to
turn PROBE OFFSET off,
before
continuing operation.
3
PUSH
PROG
Key(s)
pressed
is/are
active only in PROG CHAN
mode. To use key, first press PROG CHAN.
4
PUSH
PROG
Key(s)
pressed
is/are
active
only in PROG TRIG
mode.
To
use key,
first press PROG
TRIG.
5
AND/OR REQ
While
programming a
trigger function, a CH1,
CH2, CH3, CH4, NOT, or EDGE
was pressed when
an
AND
or
an OR key was expected.
6
CH
KEY
REQ
While
programming a
trigger function, two Boolean
operator
keys (AND or
OR) were pressed without
pressing
a
channel key (CH1, CH2, CH3, or CH4) in
between.
Channel
keys
and
Boolean operator keys
should be
pressed
alternately, e.g., CH1 AND NOT
CH2 OR CH3
EDGE.
7
OR
IS
FULL
The OR key
was pressed again. Only one TRIGGER
FUNCTION OR is
allowed.
8
EXTCLK
ON
The EDGE
key was pressed while in the EXT CLOCK
SYNC
mode.
The
selection of
an EDGE sensitive
channel and
the EXT CLOCK SYNC mode are mutually
exclusive.
If EDGE
sensitivity is desired, first turn
off
the
EXT CLOCK SYNC mode.
9
EXTCLK
REQ
The EXT CLOCK slope
key was pressed when the EXT
CLOCK SYNC button was
turned off. The EXT CLOCK
SYNC
slope key is operational only when the EXT
CLOCK
SYNC
button is
turned on.
10
EDGE IS ON
The
EXT
CLOCK SYNC
key was pressed when one of
the
trigger
functions (either
A,
B, or both) already
have
an EDGE sensitive channel. Channel EDGE
sensitivity and EXT CLOCK are mutually exclusive.
If EXT CLOCK SYNC operation is desired, first
CLEAR
the
channel EDGE sensitive
trigger function.
11
THRESH
REQ
Either
a LEVEL
key or the PROBE OFFSET key was
pressed without pressing the THRESH key first.
The
THRESH
key must
be lit to change a threshold
level
or
acquire a probe offset.
12
NO
FUNC
A
The
A THEN B key was pressed
without
having
programmed
function
A; or while in A THEN B mode
function A was
CLEARed. Both trigger functions
(A
and
B) must be programmed for proper A THEN B
operation.
Program
function
A; then proceed.
13
NO
FUNC
B
The
A THEN
B button was pressed without
having
programmed
function B; or while in A THEN B mode
function
B was CLEARed. Both trigger functions
(A and B) must be programmed for proper A THEN B
operation.
Program
function B; then continue.
WARNING BEEPS:
Although
no messages are displayed, short
warning beeps are issued
to indicate
"out of range.” A beep will sound when the VOLTS/DIV
keys
are
pushed beyond the available selections or
when the variable
threshold
level reaches
its limits.
NOTE
The
audible
beep can be turned off; refer qualified
Service Personnel to the 7A42
Service
Manual (Volume
1 ).
REV
JUL
1984
