HP 8920B, Programmer'S Manual

Page: 56 / 682

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Chapter 2, Methods For Reading Measurement Results
HP BASIC ‘MAV’ Example Program
HP BASIC ‘MAV’ Example Program
The following HP RMB example program demonstrates a technique which can be
used in situations where a 32.767 measurement result timeout value is not
adequate.
Measurement result timeout value is defined to mean the amount of time the
control program is willing to wait for the Test Set to return a valid measurement
result to the control program.
The technique uses the MAV (Message Available) bit in the Test Set’s HP-IB
Status Byte to determine when there is data in the Output Queue. A polling loop is
used to query the Status byte. The timeout duration for returning the measurement
result is handled by the polling loop. An HP-IB interface activity timeout is also
set up to handle time-outs resulting from problems with the HP-IB interface.
Lines 10 thru 230 in this example set up a measurement situation to demonstrate
the use of the recommended technique. The recommended technique is exampled
in the Measure Function.
NOTE: Lines 50 and 60 should be included in the beginning of all control program. These lines are
required to ensure that the Test Set is properly reset. This covers the case where the program
was previously run and was stopped with the Test Set in an error condition.