YOKOGAWA WT5000 User Manual page 33

The COMMunicate:OPSE command is used to
select which command to apply *OPC? to. Here, it is
applied to the media access command.
Because *OPC? does not generate a response
until the overlapping operation is completed, the file
loading will have been completed by the time the
response to *OPC? is read.
Note
Most commands are sequential commands. Overlap
commands are indicated as such in chapter 5. All other
commands are sequential commands.
Achieving Synchronization without Using
Overlap Commands
Even when using sequential commands, there
are times when it is necessary to achieve
synchronization to properly query the measured data.
For example, if you want to query the most recent
numeric data each time that the measured data is
updated, you can attempt to do this by sending the
:NUMeric[:NORMal]:VALue? command with some
arbitrary timing. However, because this instrument
returns the current measured data regardless of
whether the measured data has been updated since
the previous query, this method may return data that
is the same as the previous data. If this happens, you
must use the following method to synchronize with the
end of measured data updating.
• Using the STATus:CONDition? query
STATus:CONDition? is used to query the contents
of the condition register (see page 6-5 for details).
You can determine whether the measured data
is being updated by reading bit 0 of the condition
register. If bit 0 of the condition register is 1, the
measured data is being updated. If it is 0, the
measured data can be queried.
• Using the extended event register
The changes in the condition register can be
reflected in the extended event register (see page
6-5 for details).
Example :STATus:FILTer1 FALL;:STATus:
EESE 1;EESR?;*SRE 8<PMT>
(Read the response to STATus:EESR? )
Loop
(Wait for a service request)
:NUMeric[:NORMal]:VALue?<PMT>
(Read the response to :NUMeric[:
NORMal]:VALue? )
:STATus:EESR?<PMT>
(Read the response to STATus:EESR? )
(Return to Loop )
IM WT5000-17EN
4.5 Synchronization with the Controller
The STATus:FILTer1 FALL command sets the
transition filter so that bit 0 in the extended event
(FILTer1) is set to 1 when bit 0 in the condition
register changes from 1 to 0.
The STATus:EESE 1 command is used to only
change the status byte based on bit 0 in the
extended event register.
The STATus:EESR? command is used to clear the
extended event register.
The *SRE 8 command is used to generate service
requests based only on the changes in the extended
event register bits.
The :NUMeric[:NORMal]:VALue? command is
not executed until a service request is generated.
• Using the COMMunicate:WAIT command
The COMMunicate:WAIT command is used to wait
for a specific event to occur.
Example :STATus:FILTer1 FALL;:STATus:
EESR?<PMT>
(Read the response to STATus:EESR? )
Loop
COMMunicate:WAIT 1<PMT>
:NUMeric[:NORMal]:VALue?<PMT>
(Read the response to :NUMeric[:
NORMal]:VALue? )
:STATus:EESR?<PMT>
(Read the response to STATus:EESR? )
(Return to Loop )
For a description of STATus:FILTer1 FALL and
STATus:EESR? , see the previous section about the
extended event register.
The COMMunicate:WAIT 1 command specifies
that the program will wait for bit 0 in the extended
event register to be set to 1.
:NUMeric[:NORMal]:VALue? is not executed
until bit 0 in the extended event register becomes 1.
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App
Index
4-9