I have had my new system running for a little over a week now and just got in the hardware to setup the motherboard serial port (IE. the connectors, cable and the external port). Yesterday evening I decided to move my timing GPS (Motorola Oncore UT+) from the old machine to the new machine and I am having issues with the serial connection. The GPS is wired so that the Pulse Per Second (PPS) signal goes to the DCD pin on the port and all of the other lines are connected in the normal way through a TTL to serial converter. The GPS and related software (NTP, WinOncore12) are working fine on the old machine in both Windows XP and Linux. The new machine currently has Windows 7 and will have Linux in a few days. When connected to the new machine WinOncore12 only sees about 1 in 5 data packets from the GPS and, perhaps more disturbing, it does not see the PPS signal at all. There is clearly an issue with the serial port but I don't know what it is and the BIOS and Windows 7 settings available for the port are very limited and I have exhausted all of the things I could try using those tools.
Do I need to install a special driver for this port to get it working correctly in Windows 7? Is this one of those serial ports that does not have the DCD line connected making it useless for this type of application? Or does the DCD line on this port need unusually high voltages to activate (The PPS pulse is a 0V low to 5V high TTL signal that pulls high for 200ms every second - IE. does this port need more than a 5V pulse on the DCD line to generate an interrupt)?
Although I was using the motherboard serial port on the old machine I have a serial card that works with this GPS that I can pull from the old machine so I think I can get things working with a serial expansion card. But I would rather have the motherboard port working correctly for a number of reasons which I will not go into at this time. Hopefully someone here knows what is going on with the motherboard port.
Do I need to install a special driver for this port to get it working correctly in Windows 7? Is this one of those serial ports that does not have the DCD line connected making it useless for this type of application? Or does the DCD line on this port need unusually high voltages to activate (The PPS pulse is a 0V low to 5V high TTL signal that pulls high for 200ms every second - IE. does this port need more than a 5V pulse on the DCD line to generate an interrupt)?
Although I was using the motherboard serial port on the old machine I have a serial card that works with this GPS that I can pull from the old machine so I think I can get things working with a serial expansion card. But I would rather have the motherboard port working correctly for a number of reasons which I will not go into at this time. Hopefully someone here knows what is going on with the motherboard port.
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