58
Keysight P9241/42/43A Oscilloscopes SCPI Programmer's Guide
4
Sequential (Blocking) vs. Overlapped Commands
Pausing Programs
Until Sequential
(Blocking)
Commands are
Complete
Sequential (blocking) commands do not prevent additional commands from being
sent to the queue or cause the remote program to wait. For example, if your
program does something like:
myScope.WriteString ":DIGitize"
Debug.Print "Signal acquired."
The "Signal acquired" message will be written immediately after the :DIGitize is
sent, not after the acquisition and processing is complete.
To pause the program until a sequential (blocking) command is complete, you
must wait for a query result after the sequential (blocking) command. For example,
in this case:
Public strQueryResult As String
myScope.WriteString ":DIGitize;*OPC?"
strQueryResult = myScope.ReadString
Debug.Print "Signal acquired."
The "Signal acquired" message will be written after the acquisition and processing
is complete. The *OPC? query is appended to :DIGitize with a semi-colon (;), which
essentially ties it to the same thread in the parser. It is immediately dealt with once
:DIGitize finishes and gives a "1" back to the program (whether the program uses it
or not), allowing the program to move on.
When using a query to wait until a sequential (blocking) command is complete, it
is possible for the sequential (blocking) command execution to take longer than
the I/O timeout, in which case, there will be a timeout error while waiting for the
query results. You can increase the I/O timeout or have your program poll the
Status Byte Register using the IO libraries' unblocked ReadSTB function to wait for
execution completion.
Using Device Clear
to Abort a
Sequential
(Blocking)
Command
When sequential (blocking) commands take too long or fail to complete for some
reason, you can send a Device Clear over the bus to clear the input buffer and
output queue, reset the parser, and clear any pending commands.
See Also
•
•
"*ESR (Standard Event Status Register)"
•
Содержание P9241
Страница 1: ...Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide...
Страница 6: ...6 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide...
Страница 36: ...36 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 1 What s New...
Страница 41: ...Setting Up 2 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 41...
Страница 44: ...44 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 2 Setting Up...
Страница 222: ...222 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 7 Root Commands...
Страница 244: ...244 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 8 ACQuire Commands...
Страница 256: ...256 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 9 CALibrate Commands...
Страница 278: ...278 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 10 CHANnel n Commands...
Страница 328: ...328 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 15 EXTernal Trigger Commands...
Страница 386: ...386 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 17 FUNCtion m Commands...
Страница 390: ...390 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 18 HCOPY Commands...
Страница 416: ...416 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 20 MARKer Commands...
Страница 498: ...498 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 21 MEASure Commands...
Страница 532: ...532 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 22 MTESt Commands...
Страница 572: ...572 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 24 SAVE Commands...
Страница 596: ...596 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 25 SBUS n Commands SBUS n A429 SOURce on page 588...
Страница 900: ...900 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 28 TIMebase Commands...
Страница 1080: ...1080 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 31 WGEN w Commands...
Страница 1142: ...1142 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 34 Error Messages...
Страница 1204: ...1204 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide 37 More About Oscilloscope Commands...
Страница 1344: ...1344 Keysight P9241 42 43A Oscilloscopes SCPI Programmer s Guide Index...