Problem Using DVATX with Phidgets

Hi All -

I am having problems using the DVATX software with Phidgets to drive my TQ.

DVATX recognizes my throttles and I can perform calibration limits and test motion control using the DVATX utility. All is fine to that point. However in an actual flight whenever I try to engage my autothrottle with DVATX connected all control to the aircraft is lost. There is no auto-motion to the throttles, no physical resisitance when I attempt to move the throttles, and no throttle response when I attempt to manually move the throttles. The aircraft immediately goes into a spiraling nose dive. If I close DVATX at that point I can regain control and all goes back to normal.

Any thoughts and help on this would be much appreciated,

Thanks,
Fred

Hi Fred

I hope Diego can jump in on this.


Testing the SW only with FS is one thing - it means your Throttles are moving, as they shold.

When flying - the SW takes commands from some of the MCP commands - and to my humble opinion, this is the problem.

Are you using PM ? Or SimAvionics ? If yes - you need to set the INI file. On the top part under [seetings] you need to set the parameter to 1.

If you are using none - make sure both get the =0.

I would also check if the AILERON input in the INI file is deleted (unless you use DVATX for driving them) just set the OFFSET to 0000.

Try this and let us know what is happening.

Good luck


Isaac

Hi Isaac -

Thanks for responding here and in your private message. I will repeat myself here for the benefit of others who may be interested.

I am running PM so I do need to change the setting in the ini which was designated for SimA. I will also disable the aileron setting as suggested.....A manifestation of my problem was a sharp veering to the left with DVATX engaged.

I also have my pot inputs connected via a Bodnar board at this point. I will try changing that to the Phidgets 8/8/8 to see if it makes a difference. I need to find the right kind of Molex connectors to do that but will attempt to jury-rig something tonight to test.

Thanks again, I really want to get DVATX working since it is by far the easiest method out there. I have every confidence it will work. Will keep you posted.

Fred

Hi Fred,

As Isaac has suggested, if your plane is banking to one direction, go through the ini file and remove the value for the offset that manage flight control..ie Ailerons and Elevators..

As far as your throttles not powering, this is more than likely due to DVATX not understanding whether the A/T is being commanded or not...

You must specify that you are using PM to drive the A/T in the ini file as Isaac has mention..

Let me know how you go..

Cheers

Diego

Hi Fred

You can get the cables from Phidgets - they are cheap and good quality.

I did cut the cables in the middle so I have two connections since the connectors are the same for both sides. So from each cable you can have two which you can solder to your POT wires.

Good Luck


Isaac

Okay - All this advice has been very helpful!

Changing the ini settings for PM and disabiling the ailerons solved the problems. I also found that the pots have to be connected to the Phidgets 8/8/8.....the SW does not work if the pots are connected via my original input setup to a Bodnar board.

Considering that I have loose wires hanging everywhere for the time being (I have the Molex connectors ordered for the Phidgets board) I found that DVATX performs VERY WELL despite all that! Very simple once you understand it all! Throttle calibration and movement is very precise and surprisingly smooth! I love it!

I have not tried setting up my reversers yet. My TQ has a single pot for each throttle that is set up to handle both forward and reverse thrust via a dual linkage. Can I simply wire each throttle pot to both the forward and reverse sensor positions on the 8/8/8? Do I attach the 5V lead in both sensor positions? Or do I just attach the Analog and/or Ground leads for the second sensor? I don't want to melt anything down of course. I did not see any provision in the ini file to set up dual ranges on the same sensor....Can that be done in some way? Any advice and experience on all this would be much appreciated.

Diego - Very nice work on DVATX, thanks much. And my thanks to both you and Isaac for your very prompt responses to my questions.

Fred

Hi Fred

One POT per throttle can do both - fwd and reversers.

You CAN have 2 OFFSETS in one input. Look here:

[SENSOR_INPUT_2]
MINPOS=780
MAXPOS=991
INVERTED=0
OFFSET=089A
OFFSET2=0932
SIZE=2
MINFSVALUE=-4094
MAXFSVALUE=0
TYPE=REV
DESCRIPTION=Rev_Throttle_Lever_1

[SENSOR_INPUT_3]

MINPOS=51
MAXPOS=789
INVERTED=0
OFFSET=0000
SIZE=2
MINFSVALUE=-4094
MAXFSVALUE=0
TYPE=REV
DESCRIPTION=Rev_Throttle_Lever_2


Have fun

Isaac

Thanks Isaac -

I see that now.

Very simple!

Fred

Hi All -

I just wanted to update everyone on my findings.

I was able to get my reversers working using only a single pot for each throttle. I simply "double wired" each pot to both the "throttle" and "reverse throttle" sensor positions on the 8/8/8. All that was required was to double-wire the ground and analogue leads only - no need to wire the 5V lead to the reverser positions. I then simply calibrated the reverser sensor positions using the software to correspond to the reverser range on the pot while being sure not to overlap the range designated for the forward throttle sensor position. Works like a charm!

I found that the method discussed below as a possibility of designating 2 offsets in one input will not work since there is no provision in the software to designate 2 separate sets of range values corresponding to each offset within the same sensor.

Fred