I made the measurements with my 'scope. The voltages and waveforms are identical comparing DTR, RTS (also RXD), although I am surprised a little that the pulses on DTR are as large as they are: 2.4V swing. Must be some resistance in the supply to the drain. But the level is up at 11.6V, so those 2.4V drops cannot matter. The signals on the RXD pin are -3.6 to +8.2V for both the mfg. sw and sigrok.
So no explanation yet, and hence no solution. Is there a way to examine the serial parameters the mfg. sw uses? Perhaps the docs on the protocol are in error. On Fri, Dec 29, 2017 at 9:17 AM, Denis Heidtmann <denis.heidtm...@gmail.com> wrote: > I will make those measurements, but I am doubtful it will show anything. > The schematic I have shows DTR to be the collector and RTS to be the low > end of the emitter resistor of the output NPN. I did see solid pulses on > the emitter with sigrok. But perhaps DTR and/or RTS are pulsed when they > should not be. It is too bad my 'scope has limited record length and no > way to store the data off the 'scope. > > On Thu, Dec 28, 2017 at 11:42 PM, Russell Senior < > russ...@personaltelco.net> wrote: > >> Have you measured the voltages on DTR and RTS during the runs? >> >> Try it with sigrok and with the vendor software and see if there is a >> difference in those values. >> >> On Thu, Dec 28, 2017 at 9:51 PM, Denis Heidtmann >> <denis.heidtm...@gmail.com> wrote: >> > This saga continues. >> > >> > On the laptop with a usb-serial adapter I got to the point where the >> > commands: >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyUSB0 --show >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyUSB0 --scan >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyUSB0 --samples 10 >> > >> > behave as expected except the last one returns no data. I was advised >> to >> > try using these same commands on the desktop which has an RS232 port, >> thus >> > removing the usb-serial adapter from the picture. Good idea. >> > >> > After just guessing what serial port to use, I run the following >> command: >> > >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyS0 --scan >> > The following devices were found: >> > mastech-mas345 - MASTECH MAS345 with 1 channel: P1 >> > >> > This is the same response I got on the laptop. >> > >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyS0 --show >> > mastech-mas345 - MASTECH MAS345 with 1 channel: P1 >> > Supported driver options: >> > conn >> > serialcomm >> > Supported configuration options: >> > >> > This is the same response I got on the laptop. >> > >> > sigrok-cli --driver mastech-mas345:conn=/dev/ttyS0 --samples 10 >> > >> > [no response except the usual ~10 second delay] >> > >> > This is the same response I got on the laptop. RATS! >> > >> > This eliminates the usb-serial device from the picture. >> > >> > Recall that when running --samples 10 command on the laptop I was able >> to >> > detect pulses on the serial line consistent (in a general sense) with a >> > response from the dmm. Also recall that running the mfg. sw under >> windows >> > on the desktop showed flawless communication. >> > >> > finally, I report: >> > stty -F /dev/ttyS0 -a speed 600 baud; rows 0; columns 0; line = 0; >> > intr = <undef>; quit = <undef>; erase = <undef>; kill = <undef>; eof = >> > <undef>; >> > eol = <undef>; eol2 = <undef>; swtch = <undef>; start = <undef>; stop = >> > <undef>; >> > susp = <undef>; rprnt = <undef>; werase = <undef>; lnext = <undef>; >> > discard = <undef>; min = 0; time = 0; >> > -parenb -parodd -cmspar cs7 hupcl cstopb cread clocal -crtscts >> > -ignbrk -brkint ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon >> > -ixoff >> > -iuclc -ixany -imaxbel -iutf8 >> > -opost -olcuc -ocrnl -onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 >> bs0 >> > vt0 ff0 >> > -isig -icanon -iexten -echo -echoe -echok -echonl -noflsh -xcase -tostop >> > -echoprt >> > -echoctl -echoke -flusho -extproc >> > >> > And the protocol is reported to be: >> > >> > data format: 7n2 at 600 baud (7 bits, no parity, 2 stop bits). >> > Control lines: >> > DTR and RTS lines are used to power the TX line: RTS is clear >> > for -12 supply; DTR is set for +12 supply. Data transmission is >> > solicited sending whatever character to the RX line. >> > >> > Any suggestions as to where to go from here? >> > >> > Thanks, >> > -Denis >> > _______________________________________________ >> > PLUG mailing list >> > PLUG@pdxlinux.org >> > http://lists.pdxlinux.org/mailman/listinfo/plug >> _______________________________________________ >> PLUG mailing list >> PLUG@pdxlinux.org >> http://lists.pdxlinux.org/mailman/listinfo/plug >> > > _______________________________________________ PLUG mailing list PLUG@pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
