IO server in java

[Debora]

Hello,

I have an Ewon flexy 205 with an io extention card. For testing i have an io test card.

I want to read the values from the digital input, but I can’t find how to do this in java.
On the developers page for java is a document calledt eWON Java I/O Server interface. In this document a class IoTestServer has been created, but it doesn’t explain on how to use the class.

I want to read the value that is on the digital input as a bool. I found a way to do this in basic, but all my code is already written in java and I didn’t find a way to use self written basic routines in java.

The basic code that I found is from this post.

DoSwitch:
If (Switch@=1) Then
rem Open Internet connection
Setsys COM,"load"
Setsys COM,"WANCnx","2"
Setsys COM,"WANPermCnx","1"
Setsys COM,"save"
Print Time$;" Connection opened"
else
rem Close Internet connection
Setsys COM,"load"
Setsys COM,"WANCnx","0"
Setsys COM,"save"
Print Time$;" Connection closed"
endif

Can someone explain on how to do this? Or link me to an explanation?

[Kevin_hms]

Hello,

So the code you have listed above is our BASIC script for enabling/disabling internet via IO module. This will not work in Java.

The following link would be a better example

Enabling/disabling the WAN interface | Ewon Developers

I would also review the Tag Creation with IO document:

rg-0007-00-en-reference-guide-io-servers.pdf

[Kevin_hms]

I am alittle unclear on what you are looking for.

Do you require assistance with creating Java code to read a Tag value generated by the IO extension card?

[Debora]

Yes. Sorry that it wasn’t clear.
I want to read a tag value generated by the IO extention card.

[Debora]

I looked at these links and this is what I wanted. Thank you.

One more question. Is it possible to be detect when a tag changes values without being in a constant loop that watches the tag value?
For example that if the tag goes from 0 to 1 that it will automaticly go to a function.
Like an interrupt.

[Kevin_hms]

Hello Debora,

I would look at the ONCHANGE for Basic Scripts. This will do exactly what you want it to do. I have attached the document below.

However, we do not have the Java functionality… Java will require constant polling to detect the change.

rg-0006-01-en-basic-programming.pdf

[Debora]

Hello Kevin,

Thank you for the reply.
I haven’t worked in basic and the reference guide doesn’t really help. Can you help?
I want to detect when the digital input changes. and I want to set a tag in memory so I can read that in java and execute a function there.

I can’t write that function in Basic because of it’s size and complexity. That’s why I want to notify java. And if i can give java a string with the time it happened, I can just handel it there anytime. But I do need the time it happened. So in the memory tag I want to put a string.

So if I have a DI tag called start. And a MEM tag called stringVar.
And ONCHANGE has the following structure:
ONCHANGE"MyTag","GOTOMyTagChange"

So following that, I would need to do this:

start@ = GETSYSTAG,“start”
ONCHANGE start@, “GOTO tagChangeFunction”

tagChangeFunction:
//fill the MEM tag with a string

Is this the right way? And if it is, how do i set the content of the MEM tag?

This is how I set up the tags:

And:

[Debora]

Hello,

I managed to write the basic code. It looks like this:

GiveToJava:
Print "It works"
a% = GETSYS PRG, "Msec"
stringVar@= STR$ a%
Print stringVar@
END

When testing this, I did not get the results i wanted. I think it has something to do with too many threads that take up a lot of time.
I must work with milliseconds, so when the on change starts too late, I don’t get the right time.

So I went back to java. And wrote a loop that constantly checks the IO. I know this isn’t a nice approach and that it is very intense on the CPU, but for now it works.

I put this loop in a thread with a high priority. The other threads get a sleep function when they are not needed. This way i give more time to my pinWatcher thread.

Thank you for all your help.
Kind regards,
Debora