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Chapter 2, Methods For Reading Measurement Results
Background
This situation can be avoided entirely by:
1. sending a Selected Device Clear (SDC) interface message to put the Test Set’s HP-IB
subsystem into a known state.
2. sending a command to terminate the requested measurement cycle.
These commands issued in this order will allow the control program to regain
control of the Test Set. Any other sequence of commands will result in
unexpected operation.
The following programs demonstrate a recommended technique for querying and
entering data from the Test Set. This technique will prevent the Test Set from
getting into a ‘hung’ state such that power must be cycled on the Test Set to regain
manual or programmatic control.
There are a variety of programming constructs which can be used to implement
this technique. In the programming examples presented, a function call is
implemented which returns a numeric measurement result. The function call has
two pass parameters; the query command (passed as a quoted string) and a time-
out value (passed as a integer number).
The time-out value represents how long you want to wait, in seconds, for the Test
Set to return a valid measurement result. If a valid measurement result is not
returned by the Test Set within the time-out value, the function returns a very
large number. The calling program can check the value and take appropriate
action.
The program examples are written so as to be self-explanatory. In practice, the
length of: variable names, line labels, function names, etc., will be
implementation dependent.
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Страница 17: ...Contents 17 3 HP IB Command Guidelines Sequential and Overlapped Commands 72 Guidelines for Operation 73 ...
Страница 24: ...Contents 24 9 Error Messages ...
Страница 25: ...Contents 25 Index 593 ...
Страница 26: ...Contents 26 ...
Страница 27: ...27 1 Using HP IB ...
Страница 58: ...58 Chapter 1 Using HP IB Remote Local Modes ...
Страница 59: ...59 2 Methods For Reading Measurement Results ...
Страница 71: ...71 3 HP IB Command Guidelines ...
Страница 94: ...94 Chapter 3 HP IB Command Guidelines Guidelines for Operation ...
Страница 95: ...95 4 HP IB Commands ...
Страница 100: ...100 Adjacent Channel Power ACP ...
Страница 150: ...150 Display DISPlay space TDMA test TESTs TFReq THLP TIBasic TMAKe TPARm TPRint TSEQn TSPec Returns current screen TX ...
Страница 173: ...173 System System SYSTem ERRor Returns integer value quoted string ...
Страница 236: ...236 Triggering Measurements ...
Страница 237: ...237 5 Advanced Operations ...
Страница 350: ...350 Chapter 6 Memory Cards Mass Storage Using Memory Cards Figure 20 Inserting a Memory Card ...
Страница 360: ...360 Chapter 6 Memory Cards Mass Storage Using External Disk Drives ...
Страница 361: ...361 7 IBASIC Controller ...
Страница 442: ...442 Chapter 7 IBASIC Controller The TESTS Subsystem ...
Страница 559: ...559 Chapter 8 Programming The Call Processing Subsystem Example Programs 11280 SUBEND 11290 ...
Страница 562: ...562 Chapter 8 Programming The Call Processing Subsystem Example Programs ...
Страница 563: ...563 9 Error Messages ...
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