Agilent Technologies A.18.00 Comments for Recommended Routine

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S:\agilent\8920\8920b\PRGGUIDE\BOOK\CHAPTERS\measrslt.fb
Chapter 2, Methods For Reading Measurement Results
HP® BASIC ‘MAV’ Example Program
Comments for Recommended Routine
Table 8 Comments for Measure Function from MAV Example Program
Program Line
Number Comments
50 Send a Selected Device Clear (SDC) to the Test Set to put the GPIB subsystem
into a known state. This allows the control program to regain programmatic
control of the Test Set if it is in an error state when the program begins to run.
60 Command the Test Set to abort the currently executing measurement cycle. This
will force the Test Set to stop waiting for any measurement res ults to be available
from measurements which may be in an invalid state when the program begins to
run.
290 Turn event initiated branches off (except ON END, ON ERROR and ON
TIMEOUT) to ensure that the Measure function will not be exited until it is
finished.
300 Set up a 5 second timeout for any I/O activity on the GPIB. This will allow the
function to recover if the bus hangs for any reason. The length of t he timeout will
be implementation dependent.
310 Set the triggering mode to single followed by a trigger immediate command. This
ensures that a new measurement cycle will be started when the TRIG:IMM
command is sent. This sequence, that is: set to single trigger and then send t rigge r
command, guarantees that the measurem ent result returned to the ENTER
statement will accurately reflect the state of the DUT when the TRIG:IMM
command was sent. The ’IMM’ keyword is optional.
320 Send the query command passed to the Measure function to the Test Set.
330 Establish a start time against which to compare the measurement result timeout
value passed to the Measure function.
340 Start the status byte polling loop.
350 Allow the Test Set some time (100 milliseconds) to process the measurement.
When polling the Test Set the polling loop must give the Test Set time to process
the requested measurement. Since GPIB command processing has a higher sys-
tem priority within the Test Set than measurement functions, con stantly sending
GPIB commands will result in longer measurement times.