D100 serial stream and upgrading

[Etienne]

Hi

At the moment, my EDC-10A is sitting in my aircraft, whilst I rebuild the panel at home. I have 4 instruments that all speak to each other, and I'd like to check that the D100 is part of the group of friends.

It's running version 3 software (another question regarding that coming up). The problem I have is that I can't seem to get a serial stream of any sort out of it. Is this expected behaviour? All I want to do is check that I've wired all the instruments together correctly, so I'm not expecting sane values to come from the D100, just some form of stream.

The next question: I would like to upgrade the firmware of the D100 whilst at home (so EDC-10A not connected), with the intention of re-doing the upgrade out at the aeroplane when I install the panel and connect the EDC. It's just to get familiar with the changes, and to check that everything works. However, when I hook the D100 up to the computer, the update software complains of a communication error when checking firmware version on Com 3 (the D100 is connected via a serial->USB converter, and mounts on Com 7)... It does go through the motions of checking Com 7, but doesn't appear to find anything. Any ideas?

Thanks
Etienne

 

[dynonsupport]

It's running version 3 software (another question regarding that coming up). The problem I have is that I can't seem to get a serial stream of any sort out of it. Is this expected behaviour? All I want to do is check that I've wired all the instruments together correctly, so I'm not expecting sane values to come from the D100, just some form of stream.

So remember that the serial port that streams data does not connect the units together as of version 4, though it did from the EFIS to the EMS in version 3. In any case, you should be able to read a stream off of EFIS pin 10. You do need to have the PC or receiving device grounded to the EFIS as well.

If you're talking about DSAB - that's not an RS-232 stream, so there isn't a way to easily connect to it with a PC without a special RS-485 adapter.

However, when I hook the D100 up to the computer, the update software complains of a communication error when checking firmware version on Com 3 (the D100 is connected via a serial->USB converter, and mounts on Com 7)... It does go through the motions of checking Com 7, but doesn't appear to find anything. Any ideas

So this might indicate a more fundamental problem with your 9 pin harness wiring, and might be causing your first problem too. I'd run through the 25 pin to 9 pin wiring diagram and make sure all the wires are ending up in the right places. Like the above, the device you're checking firmware version on needs to be grounded to the PC, but this is typically handled by one of the 3 wires running to the 9 pin connector.

 

[Etienne]

Thanks... The units are 2 GPS's, a PC and the D100, so the only thing I'm looking for is that 64Hz stream.

I have been able to get it work previously using the 3 wires (Gnd, Tx and Rx), but I have since remade the harness. I do think that it's unlikely to be a problem with the D100, as long as it still spits out the stream without the EDC connected, which you've confirmed. Time to re-re-recheck that wiring :

As for the upgrade, I assume that it is ok to do it without the EDC connected, providing that when I do reconnect the EDC, I reload the V4 firmware?

Thanks

 

[dynonsupport]

I do think that it's unlikely to be a problem with the D100, as long as it still spits out the stream without the EDC connected, which you've confirmed.

Those serial ports are really robust - I don't know if we've ever seen one fail unless sent some really crazy voltage.

As for the upgrade, I assume that it is ok to do it without the EDC connected, providing that when I do reconnect the EDC, I reload the V4 firmware?

Yep.

 

[Etienne]

Thanks

 

[Etienne]

Those serial ports are really robust - I don't know if we've ever seen one fail unless sent some really crazy voltage.

Well, I found the problem... The signal ground on Serial port 1 for some reason has gone U/S. Symptoms were pretty strange - communication only happened when the two devices shared a ground (through the power bus), so once I figured that out, it pointed to the data ground not working. Checked both harnesses that I have, and the wiring was sound, so the only thing left was the actual pin on the D100.

I've swapped Serial 1 and Serial 2's ground (pins 9 and 21) as I'm not using Serial 2. It's all working now, so I'm happy. Not sure what happened to Pin 9 though. A bit of a mystery...