On Mon, Jul 05, 2021 at 01:06:35AM +0300, Paul Fertser wrote: > > > > sr: [00:00.781527] scpi_serial: Successfully sent SCPI command: 'AUTO?'. > > > sr: [00:00.989445] scpi: Got response: 'AUTVDCO?1', length 9. > > > sr: [00:00.989454] fluke-45: Response to AUTO: AUTVDCO?1. > > We see here echo intermixed with the reply to the previous FUNC1? > command. So it's "AUT" from the echo, "VDC" from the real reply to the > previous command (FUNC1?), and "O?" from echo, then "1" and then "\n" > likely from echo again. Of course, it's all timing-dependent but it's > essential to know the echo works essentially in parallel to answering > the previous request.
This is only being seen because the code does not know it needs to wait for both an echo and a response before sending the next command. What can be seen when the driver is run with echo enabled is that the echo of the first command is treated as the response of the second command, then the response of the second command treated as the response of the third, and so on getting further and further out of sync. Interleaved with this are the echoes arriving at unpredictable points. If done properly the driver would send a command, await the echo, await the response, and then send the next command. So there would never be an opportunity for output to get interleaved. I have got my Fluke 45 now and started to experiment with it. The driver does not seem very reliable at all. At sensible baudrates it seems to just get stuck in a loop sending "FUNC1?", "AUTO?", "FUNC2?", "AUTO?" and never reading any values. I will see what I can do to improve matters. My unit has both the RS232 and GPIB options, so eventually I can try to make sure it works properly with either interface, but I'll start with the serial side. Martin _______________________________________________ sigrok-devel mailing list sigrok-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sigrok-devel
