Which offsets for eng.starter switch???

[PeterH]

Hi,

this question is to all Overhead builders using pmsystems in combination with hardware. Hope you can help me here.
Here´s my question:

I´m looking for the offset I could use to drive the (B737 pmsystem) Overhead starter switch release.
In order to start the engine, the starter switch has to be turned to the left - from pos. OFF into pos. GRD. - Sofar so good.
When the engine has ignited and spooled up to a certain rpm, the switch automatically flips back into pos. OFF.
That switch is spring loaded and released by a solenoid.
So, I need to know the offset i could read out in order to activate that solenoid.

Thanks for any hint.

Best rgds

Peter

[Jan Pemöller]

Hi Peter,

you could generate your own code and offset in PM System.
Example: N1 > 22 = spring back
The exact syntax is this not!

regards
Jan

[ANDYSMITH]

Hi peter,
you could use the "engine combution" flag, 0894 engine 1 and 092C engine 2. 0 = not running and 1 = running. this changes to 1 right after you turn on the fuel lever and the engine has fired.
that would snap the starter switch at the proper time.

Andy

[Potrohkocsonya]

Try this:

if (ManEngStart1 = 0) and (fs1n2 >= 55) and fsstartflag1 then
cutout1 = 1
else
if (fsstartflag1 = 0)
cutout1 = 0
endif
endif

if cutout1 and fsstartflag1 and (ManEngStart1 = 0) then ManEngStart1 = 1


if (ManEngStart2 = 0) and (fs2n2 >= 55) then
cutout2 = 1
else
if (fsstartflag2 = 0)
cutout2 = 0
endif
endif

if cutout2 and fsstartflag2 and (ManEngStart2 = 0) then ManEngStart2 = 1

Define the two new variables (cutout1 & cutout2) as bits anywhere in sysvar.txt.

regards
Potroh

[PeterH]

Hi Andy,

thanks for your input. Will give it a try.

Best rgds

Peter

[PeterH]

Thanks Jan. Will look into it.

Best rgds

Peter

[PeterH]

Hi Potroh,

thanks a lot for your input.
What about the offsets for the starter switches (0x5610;0x5611)? Found these in development mode -> show variables. Unfortunately can´t find any info about whether they are readable too.
Thought i could just read out the values of the switches to operate the solenoid by FSBus.
In that case I could spare the logic as it is already built into pmsystem. Is that correct?

Defining individual offsets sounds very interesting, but what about conflicts with PM future assingnments? Is there a user specific offset range reserved?

Thanks and best rgds

Peter

[Potrohkocsonya]

What about the offsets for the starter switches (0x5610;0x5611)? Found these in development mode -> show variables. Unfortunately can´t find any info about whether they are readable too.
Thought i could just read out the values of the switches to operate the solenoid by FSBus.
In that case I could spare the logic as it is already built into pmsystem. Is that correct?
Defining individual offsets sounds very interesting, but what about conflicts with PM future assingnments? Is there a user specific offset range reserved?

Hi Peter,

5610 and 5611 are the offsets for the switches themselves. You need a separate offset (a single bit for each) to drive your solenoid as you want to change the switch positions by a given condition.

All offsets you find in the sysvar.txt are readable, with exeption of some stock 'write only' FS offsets, those you can find out in the FSUIPC documentation.

If you wish the 'logic' for the switch is there in the beta 173 version, but you still need a separate bit to drive your solenoid.

Defining 'individual offsets' is what all of us do when we enhance the default pmsystems logic.
If you 'just' use the default files you have a rather basic logic only, with tonnes of important things missing.
For instance I did my own logic file long ago, which is 150000 lines long and works perfectly without looking at the new versions, those that Enrico modifies time to time.

If you want your own offsets, either you use any free offsets or the easiest is to fill the Airbus specific offsets if you use Boeing and vica versa. You will never need those.
A safe range is otherwise from 0x57A0 up to 0x57FF and also the free FSUIPC offsets from 66C0-66FF.
The only difference is that offsets outside the stock pmsystems range work a bit slower.
Yet another way is to define your own offsets via LUA and FSUIPC.

regards
Potroh

[PeterH]

Hi Potroh,

thanks for your explanation. Must be **** of a work to get the logics written. What programming language is used here?
Unfortunately PM did not describe the logic commands used in pmsystem.
If I understand you correctly the stock pmsystems logic is still lacking of some systems logics as it is used in reality.

According to your proposal would following work as desired?:
Following code is part of the original pmsystem B737.lgc extended by your proposed code

//EngStart-Begin
if ManEngStart1 = 0
if fsstartflag1 = 0
if bleed1ref > 0
fsStarter1 = 1
else
fsStarter1 = 0
endif
else
manengstart1 = (fs1n2 > 50)
endif
else
if elecbus1 and drive1cover
fsstarter1 = 2
else
fsstarter1 = 0
endif
endif

if (ManEngStart1 = 0) and (fs1n2 >= 55) and fsstartflag1 then
cutout1 = 1
else
if (fsstartflag1 = 0)
cutout1 = 0
endif
endif

if cutout1 and fsstartflag1 and (ManEngStart1 = 0) then ManEngStart1 = 1

if ManEngStart2 = 0
if fsstartflag2 = 0
.............




In syvar.txt I would define:

56CB .0 cutout1
56CB .1 cutout2

(Those were Airbus variables before)


Thank you

Peter

[Potrohkocsonya]

thanks for your explanation. Must be **** of a work to get the logics written. What programming language is used here?
Unfortunately PM did not describe the logic commands used in pmsystem.
If I understand you correctly the stock pmsystems logic is still lacking of some systems logics as it is used in reality.
According to your proposal would following work as desired?

Hi Peter,

The language used with pmsystems is quite similar to basic, but it is explained in the docs. One can't do very complicated things with this method, but it just suits the purpose and you can model the systems used in an airliner. Some people think it is for the overhead logic only but actually you can do anything there. For instance I control many other sim functions from there and also I set conditions for a lot of sounds to be played via PmSounds as well.

The 'stock' logic indeed is lacking a lot of functions, but more importantly it simplifies most of them.
It is merely a very basic starting point for those who want to have it more realistic.

As I mentioned earlier, in the new (now published) version (174) the logic is there, so first you have to decide if you want to use the old code version, or the new one. Asking, because your example is from the previous version.

regards
Potroh