Using GPS

Can I use XYZBrand GPS with PassagePlus?

In principle, you can use any GPS that outputs on the NMEA 0183 protocol. This is a serial protocol and the signal needs to be converted to USB. This means that either (a) the GPS has a built-in serial:USB adapter (example: the excellent Globalsat BU-353) or (b) the GPS is connected to a multiplexor that has a built-in serial:USB adapter, or (c) the GPS or multiplexor is connected to a separate serial:USB adapter such as the Keyspan USA-19HS or the ATEN UC232A. The key thing is that the adapter, whether built-in or separate, needs to have a Mac OS X driver. If you are using an Intel Mac, the driver needs to be Universal. back

My GPS is properly connected to my Mac and the GPS unit itself seems to be working fine, but PassagePlus cannot read the signal. What's wrong?

Many GPS units have two types of output. One is proprietary to the particular manufacturer. The other is NMEA. Make sure you have set it to NMEA. back

I am using a chart that is on European 1950 datum. So I should set my GPS to European 1950 datum, right?

WRONG! It is ABSOLUTELY ESSENTIAL that your GPS is set to output NMEA data on WGS84 datum. PassagePlus will correct for the datum of the chart. If your GPS outputs NMEA on any datum other than WGS84, positions will be displayed inaccurately and could be wrong by several hundred metres or even more. back