Scanning Programming Example - Keithley 2750 User Manual

7-32 Scanning
e.
f.

Scanning programming example

The following program will scan 10 channels (101 through 110):
TRAC:CLE
INIT:CONT OFF
TRIG:SOUR IMM
TRIG:COUN 1
SAMP:COUN 10
ROUT:SCAN (@101:110)
ROUT:SCAN:TSO IMM
ROUT:SCAN:LSEL INT
READ?
SAMPle:COUNt and TRIGger:COUNt — Sample count specifies the number of
readings to scan and store in the buffer, while the trigger count specifies the num-
ber of scans to perform.
If the sample count is greater than the number of channels in the scan list (scan list
length), operation wraps around to the beginning of the scan list and continues. For
example, assume the scan list is made up of channels 101, 102, and 103, and the
sample count is set to 4. After channels 101, 102, and 103 are scanned, operation
loops around to scan channel 101 again. The first and last readings in the buffer
will be channel 101.
When performing multiple scans (trigger count >1), sample readings overwrite the
readings stored for the previous scan.
Continuous initiation must be disabled in order to set the sample counter >1 (see
Reference c).
INITiate:CONTinuous, INITiate and READ? — In order to initiate a single scan
cycle using INITiate or READ?, continuous initiation must be disabled. If you send
INIT or READ? with continuous initiation enabled, error -213 (Init ignored) will
occur.
You cannot use READ? or INITiate if sample count >1, AND there are readings
stored in the buffer by the TRAC command, or by front panel data store operation
(error -225, out of memory). Either set the sample count to one or clear the buffer
(TRACe:CLEar).
Model 2750 Multimeter/Switch System User's Manual
' Clear buffer.
' Disable continuous initiation.
' Select the immediate control source.
' Set to perform one scan.
' Set to scan 10 channels.
' Set scan list channels; 101 through 110.
' Start scan when enabled and triggered.
' Enable scan.
' Trigger scan and request the readings.