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RS232 Allocation on GX3 System..

I’m installing a GX3 system with 1 GDU 460, a GAD29, GEA24, GSU25, GTR200, GMC 507, and GNX 375 navigator. Plus a ARTEX 345 ELT, GD-40 CO2 detector, Vertical Power system.

As I am installing I am looking the RS232 allocation. The GDU has 5 RS232 connections, well technically 6 if you count the one that is the backup for the GSU25. 2 of them are taken by the 375 navigator. 1 is taken by the Vertical Power. So that leaves 2 left. Here are the things that could be hooked up.

GEA24 Backup
GTR200 Backup -This might be the first to eliminated since I can manually tune the radio if needed in the event of CanBus failure.
CO2 (RX only)
ELT (TX only)

So here are a couple of questions.
1. There is one spare RS232 spot on the 375. It has 4 I believe and I am only using 3. Can I use that for the ELT instead of the GDU?
2. Can I split a RS232 configuration. In other words for example on RS232 #5, TX on RS232 #5 to the ELT and then use the RX side of that RS232 #5 to receive from the CO2 detector.

3. And lastly concerning the CANBUS. This is a bit confusing but the way I read it, I can us the P4X01 connection Pin 1 and 2 on the GSU25 and wire it directly to the P4X01 Pin 1 and 2 on the GDU 460. Not splicing this line it, its just an additional pathway into the CANBUS. Then use the the P4X02 On the GDU, pins 45 and 46 to put the GDU in the CANBUS daisy chain and skip the GSU25. Pretty sure that’s correct but if someone can back me up.

Thanks,
 
check your artex more closely. I learned that they are set up from the factory as Aviation 9600 and cannot be changed in the field to NMEA 4800 (can only be changed at the factory or by a distributor with appropriate tool). The G3X does not have an aviation output to connect with this. It needed to come from the 430W in my case.

Never seen a 375, but curious to learn why it needs 2 RS-232 ports. Never seen that on a naviagator. If that is the new unit that includes a transponder, the transponder interface is usually via a 232 port on the GSU 25.

The G3X assigns the interface protocol to the whole port, not separately for Tx and Rx.

Larry
 
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The 375 has an internal transponder also. It has 2 ports that go to the GX3 system. That does leave 3 left. I found in the manual for the 375 you can configure RS232 port TX to “ADS-B GPS 9600 baud” The ELT is set up for 9600 baud so I am going to assume that will work.

Since I can’t split the configuration I am going to Run RS232 1 and 2 between the GDU and 375 Nav, RS232 3 to the vertical power, RS232 4 for the GEA 24 backup engine instruments, and the RS232 5 for the CO2 RX. Then I will run the RS232 #3 off of the 375 to the ELT.

Hope that makes sense.
 
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The 375 has an internal transponder also. It has 2 ports that go to the GX3 system. That does leave 3 left. I found in the manual for the 375 you can configure RS232 port TX to “ADS-B GPS 9600 baud” The ELT is set up for 9600 baud so I am going to assume that will work.

Since I can’t split the configuration I am going to Run RS232 1 and 2 between the GDU and 375 Nav, RS232 3 to the vertical power, RS232 4 for the GEA 24 backup engine instruments, and the RS232 5 for the CO2 RX. Then I will run the RS232 #3 off of the 375 to the ELT.

Hope that makes sense.

I'm pretty sure the ELT won't be able to use ADS-B format. Check the ELT manual for the unit you have it will tell you what it will accept.
 
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