Keithley 237

SECTION3
IEEE-488
Reference
+
a.s.11
M-
SRQ Mask and
Serial Poll
Byte Format
Purpose
Format
Parameters
Default
Description
3-40
To
program
which
conditions generate
an
SRQ
(service request).
M(mask},(
compliance)
mask-
Sum
of
the
binary
bits
in
the
SRQ
mask:
0 =
SRQ disabled
1
=Warning
2 =
Sweep
Done
4 = Trigger
Out
8 = Reading
Done
16
=Ready
for Trigger
32=
Error
128 = Compliance
compliance-
Allowable times
to
detect SRQ
on
compliance:
0
=
SRQ
on
compliance
when
it
occurs
during
a
delay
or
measure
phase
or
idle time.
1 = SRQ
on
compliance
when
it
occurs
in
the
measure
phase
only.
Upon
power-up,
or
after receiving a DCL,
SOC,
or
JOX
command,
the
instrument
de-
faults
to
MO,O
(SRQ
is
disabled, compliance
during
delay, measure,
or
idle).
The
SRQ
command
selects
which
conditions cause
the
Model236
/237/238
to
gener-
ate
an
SRQ (service request).
Once
an
SRQ
is
generated,
the
serial
poll
byte
can
be
checked to
determine
if
the
Model236/237
/238
was
the
instrument
that
generated
the
SRQ
and,
if
so,
what
conditions
caused
it.
An
8-bit
SRQ
mask
determines
which
conditions
cause
an
SRQ
to
be
generated.
(See
Figure 3-5.) By
sending
the
appropriate
M
command,
you
can
set
the
bit
or
bits
to
en-
able
SRQ
generation
if
those
particular conditions occur.
Possible conditions include:
•
Warning
(M1,)-
A
warning
condition
has
occurred.
•
Sweep
Done
(M2,)
-All
data
taken
is
available for reading.
•
Trigger
Out
(M4,)-
Each trigger
out,
including
an
end
of
sweep
trigger out, gen-
erates
an
SRQ.
•
Reading
Done
(M8,)
-Measurement
and
processing
of
data
is
complete.
•
Ready for Trigger
(M16,)-
The
unit
is
ready
for a trigger.
•
Error
(M32,)
-An
error
condition
has
occurred.
• Compliance (M128,)
-Compliance
occurred
during
delay
or
measure
phase
or
idle
time,
or
measurement
phase
only.
+