Model 4200A-SCS Parameter Analyzer Reference Manual
Section 9: Keithley External Control Interface (KXCI)
4200A-901-01 Rev. C / February 2017
9-43
Details
Use the trigger command string to start the testing process. In the command string, you specify the
type of measurement (voltage or current), and the SMU or voltmeter (
VM1
...
VM
n
) that makes the
measurement.
A SMU that is used to measure current is always specified in the trigger command string by its
mapped function number (1...9). The mapped function number normally corresponds to the 4200A-
SCS channel number — the physical SMU number. You can map non-corresponding SMU function
numbers, but it is not recommended. However, because you can use a SMU to measure voltage
either directly (as mapped
SMU1
...
SMU9
) or as a mapped voltmeter (
VM1
...
VM9
), the SMU is specified
in the trigger command string by a unique identifier. For example, a physical SMU that has been
mapped as
SMU5
(using KCon) is specified by the unique identifier
7
.
After sending the command string to trigger a measurement and addressing the 4200A-SCS to talk,
the output data string is sent to the computer in the following format:
X
Y
Z
±
N
.
NNNN
E±
NN
Where:
•
X
: The status of the data (where
X
=
N
for a normal reading)
•
Y
: The measure channel (
Y
=
A
through
F
)
•
Z
: The measure mode (
Z
=
V
or
I
)
•
±
N.NNNN
E±
NN
is the reading (mantissa and exponent)
When channels are mapped to different functions (
VM
or
VS
), KXCI tries to trigger measurements on
the specified channels. However, if the mapped function for a channel does not match the requested
measurement, KXCI reports an error. For example, if the mapped function for a channel is
VS2
, but
the requested measurement is
TI2
, KXCI reports an error, because a
VS
cannot measure current.
Also see
None
Commands common to system and user modes
The following command strings are valid in both the system and user operating modes, and are used
for the following operations:
•
Set integration time
•
Control service request for Data Ready
•
Clear data buffer
•
Obtain firmware revision levels
•
Set global measurement resolution
•
Set the lowest current-measurement range
•
Auto calibration
•
Exit on compliance
•
Switch between 4200A and 4145 modes
