Keithley 236 Service Manual

SECTION
3
Maintenance
Message
Expianation
CAL INVALID
ERR
On powerup,
this
message wffl indicate
that
one
or more
calibration
errors
exist.
The
Model
236/237 needs
to
be
recalibrated.
CAL
CONSTANTS
ERR
One or
more calibration
constants
are not within
allowable limits. Default
cal
constants
will
be
used. Try
re-calibrating
the Model
236/237.
Repeated
failures
may indicate
de
fective
E 2 ROM
(U33).
IoU CAL
CHECKSUM
Checksum
test
of
calibration
constants failed.
Try re-calibrating the
instrument.
Re-
peated failures
may indicate
a defective
E 2 ROM
(U33).
UNCALIBRATED
There are
no
calibration
constants stored in memory.
The
E 2 ROM
(U33)
may
be
defec
tive. Note that the
Source Measure
indicator
light
blinks.
IoU
DPRAM
FAILED
The dual-port
RAM
for
the I/O
controller
has
failed making
the instrument non-func
tionaL The DPRAM
(U12)
may be defective.
IoU
EEROM FAILED
The E2ROM
(U33)
in
the I/O
controller has
failed
making
the instrument
non-func
tional.
DPRAM
LOCKUP
The source/measure
controller
cannot
respond
to
the
I/O
controller due
to
RAM
(U13),
EPROM
(U17),
or microprocessor
(U25)
failure. The
instrument
is non-func
tional.
DPRAM
LINK
ERR
Communications
error in
the
DPRAM
(U12)
between the
I/O
controller
and the
source/measure
controller.
The
unit is
non-functional.
1F
IoU RAM
(U30)
failure.
Unit is
non-functional.
2F
IoU
EPROM
(U31)
failure.
Unit is
non-functional.
Note:
There
are
error
messages
associated with
calibration
and
are
covered
in the
calibration
section
of this
manual.

Keithley 236 Specifications

General

Voltage Source Range	±100V
Current Source Range	±100 mA
Voltage Measure Range	±100V
Current Measure Range	±100 mA
Voltage Range	±100V
Current Range	±100 mA
Type	Source Measure Unit (SMU)
Compliance Limit	Programmable
Interface	IEEE-488
Resolution	5.5 digits
Operating Modes	Voltage source, Current source, Voltage measure, Current measure