Hello again,
during our progress with configuring the NI PCI-5421 for our needs
using a combination of scripting and streaming a very large waveform we
encountered anouther problem:
The goal ist not to repeadedly generate a subset of the waveform, but only to generate it once while keeping the last value constant until another trigger arrives.
The subset-size was increased from 8 to 64 samples in order to genreate a small ramp to connect the last generated value with a new one. (In contrast to generating step-functions).
The generated script therefore was changed to the following:
Script myScript
Repeat forever
Wait
until scriptTrigger0
Generate waveformName subset(0,64)
Wait until scriptTrigger0
Generate waveformName subset(64,64)
Wait until scriptTrigger0
Generate waveformName subset(128,64)
...
Wait until scriptTrigger0
Generate waveformName subset(n-64,64)
end
repeat
end Script
The subset is generated and the output remains at the last generated level until the next trigger arrives. This works well as long as we are not using streaming.
When using streaming in this configuration, the controller after some time reports enough space available to write the next "reload block" however the actual writing fails reporting that there is not enough space available.
My test-configuration was (this time using a shorter subset size of 8 samples per subset, nevertheless the error occurs with 64 samples per subset as well):
Initial Block written to the signal generator: 24960*8 samples
Reload Blocks: 19968 samples each (exactly 10% of the Initial Block)
Script: similar to the one above
Reported errors:
Space available: 29440
22.10.2007 15:59:16: writing reload block #1/1: There is not enough available room in the streaming waveform to complete the write operation.
Before writing to a streaming waveform, ensure that the space available in the streaming waveform exceeds the size of your data.
Waveform Name:
waveformName Status Code: -219105
At this point I do not understand why the writing fails as enough free samples are reported by the signal generator. I hope you will be able to help me with this one.
[edit]
strangely it takes several seconds until this error message is reported, normally it only takes some milliseconds until the block is written
[/edit]
Regards,
Lars Schönemann
Message Edited by SysEngineer on 10-22-2007 09:26 AM
Message Edited by SysEngineer on 10-22-2007 09:27 AM
