Offset &H07F2 (V/S Value)

[braunewell]

Hi guys,

as the FSUIPC Documentation or FS interrogate says, i extract the offset &H07F2.

The results are ok as far as i have a positive climbrate in the FS (like 2200). But when i change the rate to a negative value, the offset delivers a value like for example 65436 for a descentrate of -100 ft.

Has anyone a idea how to work with that?

Thanks

Stefan

[braunewell]

Hi guys,

as the FSUIPC Documentation or FS interrogate says, i extract the offset &H07F2.

The results are ok as far as i have a positive climbrate in the FS (like 2200). But when i change the rate to a negative value, the offset delivers a value like for example 65436 for a descentrate of -100 ft.

Has anyone a idea how to work with that?

Thanks

Stefan

[hastim]

stefan,

That is how negatives are held in a 2 byte (word).

if you copy this to an integer variable you should get -100.

Mark

[hastim]

stefan,

That is how negatives are held in a 2 byte (word).

if you copy this to an integer variable you should get -100.

Mark

[braunewell]

Hi Mark,

i have tried that out, copying the value from the offset to a long variable (int is too short) and it is not working.

How would you copy? may i have an example?

thanks

stefan

[braunewell]

Hi Mark,

i have tried that out, copying the value from the offset to a long variable (int is too short) and it is not working.

How would you copy? may i have an example?

thanks

stefan

[Chris Brett]

Or you could do (pseudo code):

if value from IPC > 32737 then VS := value - 65535 else VS := value;

... in the absence of knowing what the VB equivalent of a signed word is. It's a bit crude but it'll do the job.

Chris

[Chris Brett]

Or you could do (pseudo code):

if value from IPC > 32737 then VS := value - 65535 else VS := value;

... in the absence of knowing what the VB equivalent of a signed word is. It's a bit crude but it'll do the job.

Chris

[jcboliveira]

Why the long? The var is 2 byte long. I think that if you pass a long the two most signigficant bytes will be 0 on return (or something that is on 0z7f4 0x7f5 I don't know) and the negative numbers will be intrepreted as positive like in the word. If you need a long for after processing you must cast the result to it after retrieving.

Best

José

[jcboliveira]

Why the long? The var is 2 byte long. I think that if you pass a long the two most signigficant bytes will be 0 on return (or something that is on 0z7f4 0x7f5 I don't know) and the negative numbers will be intrepreted as positive like in the word. If you need a long for after processing you must cast the result to it after retrieving.

Best

José

[hastim]

I use Delphi and also not sure of the VB var equivalent.

So if you're still having problems, I'd go with Chris' example...

It will work...

Mark

[hastim]

I use Delphi and also not sure of the VB var equivalent.

So if you're still having problems, I'd go with Chris' example...

It will work...

Mark