PMDG 737 and FSUIPC7 custom offsets zero

[Luke Kolin]

PMDG has apparently changed their SimConnect API a little (AircraftModel is now 16-bit, not 8-bit) and this has cased some cascading issues downstream. I'm getting zeroes for all offsets above 6c64 (that's as far upstream as I have checked) and I am certainly not getting the Aircraft model.

I am enclosing the latest header file. When you get back John, can you check if FSUIPC 7.3.12 still works with the newest PMDG 737 for MSFS? I have 3.0.54 and am happy to validate test builds.

Cheers

 

pmdg_ng3_sdk.h

[John Dowson]

On 12/30/2022 at 3:06 PM, Luke Kolin said:

can you check if FSUIPC 7.3.12 still works with the newest PMDG 737 for MSFS? I have 3.0.54 and am happy to validate test builds.

The current version of FSUIPC7 is 7.3.15, so I can only check with that (only latest version is supported), and the latest PMDG version is now 3.0.56, so I will check with that...I have also received a message from PMDG tech support informing me of this change.

On 12/30/2022 at 3:06 PM, Luke Kolin said:

I'm getting zeroes for all offsets above 6c64 (that's as far upstream as I have checked) and I am certainly not getting the Aircraft model.

Looking at the latest header file, it is only the AircraftModel that has changed size, which is held in offset 6C8D, so only this offset and those after it (WeightInKg, GPWS_V1CallEnabled and GroundConnAvailable) should be affected. I will update the documentation  - there shouldn't be a code change necessary, but I will check. This should be the new offset allocation if you can check:

6C8E

2

BYTE x 2

AircraftModel

6C90	1	BYTE	WeightInKg
6C91	1	BYTE	GPWS_V1CallEnabled
6C92	1	BYTE	GroundConnAvailable
6C93	Last byte of first reserved area for PMDG 737

Note that as this change is near the end of the allocated offset area, I will shift those other 3 offsets down, rather than spoofing or moving the Aircraft Model offset. Hope thats ok.

John

 

[Luke Kolin]

8 hours ago, John Dowson said:

Looking at the latest header file, it is only the AircraftModel that has changed size, which is held in offset 6C8D, so only this offset and those after it

It's been way too long since I did this regularly, but if the data element increased in size from 8 to 16 bits, wouldn't the offset stay the same and just the following three increment by one? I was reading 16-bits from 6C8D before and not getting a good answer. If AircraftModel is the only element in the SimConnect structure that changed, why did its offset change?

Cheers!

[John Dowson]

12 hours ago, Luke Kolin said:

It's been way too long since I did this regularly, but if the data element increased in size from 8 to 16 bits, wouldn't the offset stay the same and just the following three increment by one?

Not necessarily. It changes from an unsigned char (1 byte) to an unsigned short (2 bytes). Not only does the size increase, but 2-byte data type must be stored on a 2-byte boundary, so it can't be on 6C8D and moves to 6C8E.

Did you take a look to see if the AircraftModel is held in that offset? I will check this layer...

John

 

[John Dowson]

@Luke Kolin Attached is the latest beta, 7.3.16b, if you would like to try with this:

FSUIPC7.exe

I checked offset 0x6C8E here and that looks to be holding the correct value for AircraftModel (3 for the 737-700 BW).

John