Setting Transponder codes with rotary switches

[B738bbjsim]

I have a Gables Transponder head containing 4 rotary switches which increment or decrement the thousands, hundreds, tens and units depending which way they are turned. I see there are FS offsets for these values. What I cannot see is how to interface this unit to the sim. Normally there would be one (or more) common connection and 8 or 9 outputs from each switch. Is there any way to record (from a starting position, maybe the default xpdr setting) how many turns a rotary switch makes and in what direction, then send it to the appropriate offset? I have FDT Simboards available.

[Pete Dowson]

I have a Gables Transponder head containing 4 rotary switches which increment or decrement the thousands, hundreds, tens and units depending which way they are turned. I see there are FS offsets for these values. What I cannot see is how to interface this unit to the sim.

Are you writing a program to provide this interface? How is it connected?

Normally there would be one (or more) common connection and 8 or 9 outputs from each switch.

Really? That's a multi-way rotary selector switch then? most rotary switches these days are "encoders" which have a common and 2 or 3 other connections, with the signals on those merely indicating the direction in which the rotary is turned, and pulsing as it is turned.

Is there any way to record (from a starting position, maybe the default xpdr setting) how many turns a rotary switch makes and in what direction, then send it to the appropriate offset? I have FDT Simboards available.

I'm certain it must be possible for you to write a program to do such things. I'm afraid I've no idea what an "FDT Simboard" is, nor exactly what your switches look like.

I think you might be better off posting hardware interfacing questions to a cockpit builders Forum. There's one near here which might help. If you then have any FSUIPC programming questions, do come back.

Regards

Pete

[B738bbjsim]

Thanks Peter,

the boards I have are Flight Deck Technology Simboards. They support programming for switches to provide events on turn on or off or change state. The problem is although I can easily enough represent the 4 digit value for the transponder I can find no way to input that to FS. Can I use transponder set to do that? If so, what form does the value take, HEX or BCD?

All I can see the other offsets doing is incrementing or decrementing the values on the FS radio stack as though clicked on by a mouse.

I will endeavour to find a programming method which would use the increasing or decreasing resistance of a potentiometer ladder to indicate the direction the switch is turning as well as its displayed value. Whilst I agree that rotary encoders are easier to use than rotary switches, modern radios lack the prestige of these antique avionics!

I, and others have in the past posted similar questions elsewhere. The response unfortunately always seems to be along the lines of "if you find out, let me know, I want to do that too!"

[Pete Dowson]

the boards I have are Flight Deck Technology Simboards. They support programming for switches to provide events on turn on or off or change state. The problem is although I can easily enough represent the 4 digit value for the transponder I can find no way to input that to FS. Can I use transponder set to do that? If so, what form does the value take, HEX or BCD?

"XPNDR SET" takes a BCD value as its parameter (e.g. 0x1234 for 1234). You could easily have tried it to see what it did. No harm would have befallen you!

I gave up trying to document FS's controls years ago. The last/best effort I ever did was in FS2000 days, and pretty much all of that still applies, except of course that it doesn't include new controls added since. You'll find the FS2000 controls document still available on http://www.schiratti.com/dowson.

For controls actually used in FS or added panels you can use FSUIPC's "Event" logging -- when you operate the control, by keyboard or mouse, the log will show if that was done by a control and if so which it was and what parameter it used, if any.

Regards

Pete