What you are describing happens to me when the either the CTS/RTS or DTR/DSR wires in your cable are crossed.
Example. The CTS pin listens (checks for voltage) to the RTS pin on the other end. If you have a cable where RTS goes straight to RTS and CTS going straight to CTS, then you have two ends of the cable both feeding voltage to the same wire. This causes the screen to go dim. the DTR/DSR pins can produce the same issue. Kurt On Tue, Apr 9, 2019, at 5:33 AM, Thomas Morehouse wrote: > Now that I've got my usb/serial link working (M102 to Dell laptop), I notice > the 102's screen get quite dim when the cable is in the 102's 25 pin serial > port. > > Doesn't need to be connected to the Dell. Just when you plug the usb/serial > cable into the 102. Unplug the cable, 102 screen returns to normal visibility. > > Something to worry about? or just live with it? I wouldn't have thought the > usb/serial cable chip would put such a drain on the system. Happens with > battery power, or even with external 6 volt poweer. > > Thanks. > Tom M. >
