With your instructions I generated signal with U=10V (with “negative peak to zero”), f=25kHz (T=40us) by lib-file with this content:
-1.0 (6144)
(0)
1.0 (1024)
(0)
-1.0 (1024)
[color=#BF0000]http://img-fotki.yandex.ru/get/5103/juleo2008.1/0_444ce_4c7b9d08_L.jpg (green plot).[/color]
I tried your bit-file with FPGA modification (inverse Sync TTL output) - it works just fine!
[color=#BF0000]4.1 5V limit on Sync TTL output - is it hardware or software limit? I.e. can it be programmed to be 10V?[/color]
Right now I encountered another task (I don’t like word “problem”, 'cause problems have tendency to get worser and worser, while tasks have tendency to be solved) - [color=#BF0000]to get simultaneously second signal (red plot), but with usual form (square, 10V, the same frequency as main signal, phase-shifted)[/color].
I’ve read http://forum.velleman.eu/viewtopic.php?f=11&t=4592, but it’s not evident if this decision will work in my case.
It would be very kind of you to suggest the way to solve this task by use of PCGU1000’s potential. Probably with some additional FPGA modifications if they are not very complex. Actually I’m a programmer, so if Velleman can trust me some uncompiled code, I can change and compile it myself.
I wrote a lot of lib-files for different signals by hands and right now I have hard intention to automate process of creating lib-file, so I could manage the signal from C+±programm. I saw there is a dll-file to include in program. Will your modifications in bin-file stay working if I try to manage PCGU1000 not from PClab, but from C+±program?
It’s nice to see that you feel the programmable waveforms of the PCGU1000 are useful.
[quote]5V limit on Sync TTL output - is it hardware or software limit? I.e. can it be programmed to be 10V?[/quote]This is hardware limited. So there is no possibility to increase the signal amplitude. You may have to use an external amplifier.
[quote]to get simultaneously second signal (red plot), but with usual form (square, 10V, the same frequency as main signal, phase-shifted).[/quote]I think the easiest way to get phase shift between the signal output and the sync output is to create a library waveform having phase shift. E.g. create a library sine wave and start it from selected phase.
Here an example. The phase shift is 30 degrees.
Here the phase shifted signal and sync pulse on the oscilloscope screen:
[quote]I’ve read viewtopic.php?f=11&t=4592, but it’s not evident if this decision will work in my case.[/quote] Could you please specify the problem more detailed for possible solution…
[quote]I saw there is a dll-file to include in program. Will your modifications in bin-file stay working if I try to manage PCGU1000 not from PClab, but from C+±program?[/quote]The modified .bit file should be usable with the FGULINK.DLL too. Just replace and rename the original fgu1000.bit with the modified pcgu1000.bit in the folder where the FGULINK.DLL and the FGU.EXE exist.
[quote]I.e. I need two phase-shifted signals: when main signal is 10V sync signal is already (several microseconds before) 5V, when main signal is 0V sync signal is still 5V forawhile and then goes to 0V.[/quote]Yes, this is possible with the library waveform.
[quote]Will setting “negative peak to zero” be accessable from C+±program to? I.e. if I manage all process from C++program, will I be able to set in on?[/quote]The option “Auto Offset (Negative peak at 0V)” is not accessible via the DLL. You have to use offset setting to achieve the same effect (e.g. amplitude 10Vpp, offset +5V).
[quote]The option “Auto Offset (Negative peak at 0V)” is not accessible via the DLL. You have to use offset setting to achieve the same effect (e.g. amplitude 10Vpp, offset +5V).
[/quote]
Will this affect sync signal too? Second signal should be 0V - +5V (not -2.5V - +2.5V).
[quote]Will this affect sync signal too? Second signal should be 0V - +5V (not -2.5V - +2.5V).[/quote]The offset affects only the output signal. The sync signal is always 0V to +5V.
