Using and setting up Ecoda 22K switch on Traxis 3500

[gillham]

Ok, I tested some more switches. I also stuck an LNB on the first port in case there was an issue with load. My receiver was providing about 13V and I tried 22Khz, SW21, DP21, DiSEqC switches.

Always provide power on both ports:
ECODA 22Khz
Original Dish SW-21
Original Dish DP-21

Provide no/low voltage on inactive ports:
DMSI 22Khz
DMSI 2x1 DiSEqC
Coolsat 4x1 DiSEqC (~0.700V on inactive)

So it seems the "always power passing" switches wouldn't be a good choice with two motors. The DiSEqC commands are not passed through the switches that only power the active port. I wonder if it is more of an issue with the motor command being sent prior to the 22Khz tone being enabled.

I guess I need to test the first group with load on both ports, but I couldn't find my basic analog meter earlier to use as a power LED.

 

[GreatFTA]

I wonder about that, too.
Maybe the fta receivers are designed only to run one motor drive, having to modify the software to handle it that way. Remember, even back to the C band days all IRDs handled one motorized dish.
It is a shame that the DiSEqc switches are not strong enough to handle this task.

 

[GreatFTA]

I am going to email DMS about this and see what their response will be. Maybe they can help...

 

[gillham]

On a side note you might be able to get something mostly working by setting the motor limits on each motor. (set this with only one motor plugged in at once of course)

For dish one, set the West limit to about 108°.
For dish two, set the East limit to about 108°.

Then if you're using USALS and send a Goto-X command for 72°W, then only dish one should move. Dish two will refuse to move as it is outside of its limit. Similar for something like 123°W, except dish one should refuse to move past 108°W.

I believe since you're telling the motor to go directly to something outside the limit, it should stay exactly where it is rather than running over to the limit and stopping. If that is not the case, then this wouldn't really help the problem much beyond stopping the dish at the limit.

 

[gillham]

Also, to limit current draw you could potentially add a DiSEqC switch after each motor and put the LNBFs on different ports. So dish one's LNBF would be on switch one, port 1. Dish two's LNBF would be on switch two, port 2.

If the switches add 25mA each, you're adding 50mA draw, but you should only have one LNBF powered up at a time which saves a net 100mA. Since when selecting a dish one satellite the receiver would send a DiSEqC port 1 command that will go to both switches, the dish two switch should also select port 1 which will have no load on it.

So in theory load would be:
25mA -- ECODA 22Khz
50mA -- standby motor
350mA -- moving motor max
50mA -- 2 x DiSEqC switch
150mA -- active LNBF
=====
625mA max

Versus:
25mA -- ECODA 22Khz
50mA -- standby motor
350mA -- moving motor max
300mA -- 2 x active LNBF
=====
725mA max

And the situation you have right now without any motor limits:
25mA -- ECODA 22Khz
700mA -- 2 x moving motor max
300mA -- 2 x active LNBF
=====
1025mA max

Of course 625mA is still well over the typical 500mA rating of a receiver, but not more than two times like now!

 

[GreatFTA]

Wow, I never thought about the limits...
I never fooled with them. I will let you know when I try that.
Thanks!

 

[GreatFTA]

Ok, guys, there are info in the "Ecoda 22Khz reliability" thread. Some of you, like me, was hoping to run two motorized from one receiver using the Ecoda switch. It won't work. Please read that thread so you won't BBQ your FTA system.
The guys in that thread really gave me great info. Many thanks to them!!!
Sorry about the bad news...
Got to get out my booger hanky, tears are still flowing... (sniff...)

 

[GreatFTA]

Oh! You guys on this thread are a great help to me, too! Thank you so much!