Re: DSO112A serial interface docs?
Posted: Fri Jul 29, 2016 6:35 pm
Before sending a "Connect" frame to start capturing data, I always send a "Set parameters" frame that updates the values on the scope to whatever the user has set them to in sigrok.
If the scope is set to 20ms originally, it works fine. Until I try to change the timebase to 50ms or larger. I don't get a confirmation back from the set parameters frame, but the timebase does change. So do other settings. My code sends a Disconnect frame after that failure (forcing the scope to be in the mode I think it's in if the confirmation got lost), and I don't get a confirmation from that either.
If the scope is set to 50ms originally, it doesn't send back the confirmation for the "Set parameters" frame, even if I change the timebase to 20ms in that frame. It doesn't change the timebase or other settings, so it may be losing the frame completely. And I get the same behavior for the Disconnect frame.
On the issue with glitches, I'm starting to think that's in the scope. After receiving a frame (always a large one at this point), it looks like I get back a NULL byte before the first sync, try the read again immediately, and there's a delay of .2 seconds before I get the 0xFE byte. I've still got some checking to do, but thought I'd mention it in case you get to the code before I do. I'll update here when I get the testing done.
Finally, an unrelated reqeust: any chance of getting the DSO062's "output trigger" option on the 112A? I'm wanting a second scope if I can get that feature, and it seems like the DSO068 doesn't have it, so adding it to the 112A would let me go with the 068, which I'd really rather have.
If the scope is set to 20ms originally, it works fine. Until I try to change the timebase to 50ms or larger. I don't get a confirmation back from the set parameters frame, but the timebase does change. So do other settings. My code sends a Disconnect frame after that failure (forcing the scope to be in the mode I think it's in if the confirmation got lost), and I don't get a confirmation from that either.
If the scope is set to 50ms originally, it doesn't send back the confirmation for the "Set parameters" frame, even if I change the timebase to 20ms in that frame. It doesn't change the timebase or other settings, so it may be losing the frame completely. And I get the same behavior for the Disconnect frame.
On the issue with glitches, I'm starting to think that's in the scope. After receiving a frame (always a large one at this point), it looks like I get back a NULL byte before the first sync, try the read again immediately, and there's a delay of .2 seconds before I get the 0xFE byte. I've still got some checking to do, but thought I'd mention it in case you get to the code before I do. I'll update here when I get the testing done.
Finally, an unrelated reqeust: any chance of getting the DSO062's "output trigger" option on the 112A? I'm wanting a second scope if I can get that feature, and it seems like the DSO068 doesn't have it, so adding it to the 112A would let me go with the 068, which I'd really rather have.