I had the same problem with some other devices, and I took apart several converters. Most of them were unable to generate sufficient levels for a proper communication with rs232. Internal charge pump was generating +-6V instead of +-12 or +-15 that is normal for rs232.
Putting additional +-12 V source on the psu pins of the converter chip might help. Predrag Dukic At 10:58 24.9.2008, you wrote: >Hi, >I have just spent a week or two trying to talk to a Trimble Thunderbolt. >I have a laptop running VISTA, about which there is little to say. >The laptop has no serial ports, but I have some USB/Serial converters >that successfully run >my HP 3815A and a Samsung GCRU/D, and also communicate with my HOBO >loggers. >The USB/Serial converters are a little difficult to use, sometimes >hanging, necessitating >unplugging and plugging back in. They get assigned to various Port >numbers but tend to keep >the same number from day to day. The ports can be configured in the >management function. >However the TBOLT refuses to talk to the converter, to the extent >that I thought that I must have >damaged the TBOLT. >Today, as a last resort, I remembered an old PC, dragged it out and >stoked it up, and to my delight >the TBOLT monitoring program ran without difficulty under Windows >2000 with a conventional serial port. >Now I vaguely remember talk about RS232 communications and the need >for pull up or down >resistors and supplies, but searching the archives I could find >nothing relevant. >Can anyone tell me how I could run the TBOLT off a USB/Serial converter? >cheers, Neville Michie > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
