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Save your Win 3.1 notebook for NMEA testing.....
I've salvaged an old Windows 3.1 notebook from a closet and am using
it as a NMEA network tester to see what's on the networks of Lionheart and its neighbors with data problems. I made up a little serial test cable with a DB9 serial plug on one end to hook to the notebook with a 6' coax cable terminated in flea clips from Radio Shack to tap into anyone's network data stream at any point in their sick system. One lead goes to notebook ground, DB9 pin 5, (NMEA -) and the other goes to pin 2, (NMEA +). The handshake lines are jumpered to each other to make sure the terminal program is always running in the top diagram of webpage: http://www.aggsoft.com/rs232-pinout-...sfer-cable.htm The PC TX line (pin 3) isn't connected to anything. The PC is only used to monitor what's going on, a data reader. Windows 3.1 boots much faster than 95/98/2000/ME/XP as it's a much smaller, simpler operating system. 3.1 also has the familiar Hyperterm simple terminal program which I've simply configured to look at the serial port at 4800 baud, 8/N/1 standard NMEA data speed. Changing it is simple for other data speeds. The old notebook allows me to watch the data streaming across the network and will save the data stream to disk for later review, if I like. I even got the old gelcell battery to take a charge. On such a slow processor with so little memory and disk drive, it'll run over 4 hours on a charge, plenty of time to test any system. If someone has hooked up two talkers the output just goes crazy, of course..... Larry I needed this to figure out which of just two pieces in a simple NMEA connection was "bad". The guy had a Garmin GPS hooked to a Yeoman Sport XL plotter. I confirmed the wires were connected properly and nothing was shorted out. I could see data flowing on the NMEA lines with my Radio Shack Data Probe, but had no way of looking at the data to see if it were valid. It wasn't. The Garmin was transmitting garbage and has been returned for repair. To confirm it, I took my Eagle handheld GPS and hooked it to the Yeoman, which instantly found its position on the chart, to the delight of its owner. He'll use his handheld until the Garmin comes back. Great use for an old notebook with no real home any more. Even a DOS notebook will work if you feed DOS a redirect to send serial port data to the console or use any old terminal program that'll run under DOS..... Larry W4CSC "Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!" |
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