STiMULi
Member
Before working on setting up my new BCD996T I had done a little research on taking the NMEA output from one GPS and supporting a scanner and a Laptop. I also wanted to eventually use the same GPS to support my TMD700A for APRS.
I had first though about a Y cable like the one found here:
http://www.pccables.com/00819.htm
The only problem with that is if you are running 2 devices that want to send information to GPS they would be in competition with each other and corrupt the transmit signal. This means the transmit lead would have to cut and with a premade cable that would be tough to do without damaging the integrity of the cable.
Some applications or devices want to send waypoints to a GPS. The TMD700A uses this function to show stations local to the radio. APRS software does the same as well as some Navagational software uses it to display the gas stations and Subway sandwich spots.
I decided instead just to use phone cable (line cord) and RJ11 to DB9M or DB9F to acomplish this.
Pins 2,3 and 5 are the pins used for simple serial commuications on the DB9.
2 = XMIT
3 = RCV
5 = GND
So it became simple use the GREEN, RED and BLACK leads on one end and the RED GREEN and YELLOW leads on the other. This depends on the line cord used. For devices that you want to prohibit sending info just don't connect the "2" pin. This would eliminate the transmit from that device.
Then you plug it all into a telephone line splitter (267A). There are 2 different types one will split all 4 conductors from one input to two outputs (in a manner that would split one line to 2 phones) or the other type (267B) which splits the RED and GREEN from the BLACK and YELLOW leads (in a manner that would support 2 lines on one telephone jack and splitting 2 Phones)
There are 3 way splitters out there. SOme combine the properties of both the 267A and 267B but most 3ways are a lager version of the 267A. Remember 267A is what you want. If I had more time I would have taken the single GARMIN LEGEND and out put it to the BCD996T, TMD700A and the LAPTOP running Delorme SA using a 3 way splitter.
There has been a suggestion to use a product called GpsGATE.This seems to be a "software" only application and will not address multiple physical serial ports.
From the GpsGATE website:
I will take photos and draw pictures when I get time
I had first though about a Y cable like the one found here:
http://www.pccables.com/00819.htm
The only problem with that is if you are running 2 devices that want to send information to GPS they would be in competition with each other and corrupt the transmit signal. This means the transmit lead would have to cut and with a premade cable that would be tough to do without damaging the integrity of the cable.
Some applications or devices want to send waypoints to a GPS. The TMD700A uses this function to show stations local to the radio. APRS software does the same as well as some Navagational software uses it to display the gas stations and Subway sandwich spots.
I decided instead just to use phone cable (line cord) and RJ11 to DB9M or DB9F to acomplish this.
Pins 2,3 and 5 are the pins used for simple serial commuications on the DB9.
2 = XMIT
3 = RCV
5 = GND
So it became simple use the GREEN, RED and BLACK leads on one end and the RED GREEN and YELLOW leads on the other. This depends on the line cord used. For devices that you want to prohibit sending info just don't connect the "2" pin. This would eliminate the transmit from that device.
Then you plug it all into a telephone line splitter (267A). There are 2 different types one will split all 4 conductors from one input to two outputs (in a manner that would split one line to 2 phones) or the other type (267B) which splits the RED and GREEN from the BLACK and YELLOW leads (in a manner that would support 2 lines on one telephone jack and splitting 2 Phones)
There are 3 way splitters out there. SOme combine the properties of both the 267A and 267B but most 3ways are a lager version of the 267A. Remember 267A is what you want. If I had more time I would have taken the single GARMIN LEGEND and out put it to the BCD996T, TMD700A and the LAPTOP running Delorme SA using a 3 way splitter.
There has been a suggestion to use a product called GpsGATE.This seems to be a "software" only application and will not address multiple physical serial ports.
From the GpsGATE website:
GpsGate supports NMEA and Garmin USB as input and creates virtual serial ports for each GPS enabled application. The virtual serial port supports NMEA.
I will take photos and draw pictures when I get time