HS/FS Python syntax

[Warichet]

Hi,

I'l having a problem with the logical "AND" in the conditional part of the Python expression.

5012|0|"(EN[9] & 1)"|"EN[1]"|""|1|0|0|0
5012|0|"(EN[9] & 2)"|"EN[2]"|""|2|0|0|0

I'm trying to do a bit wise test on a 8 bit status byte (0-255).
If the input value EN[9] = 3 and I do a logical "AND" with 1, the result should be non-zero (i.e. 1 in this case) and the formula should be executed. Right ?

If the input value EN[9] = 3 and I do a logical "AND" with 4 (or 8 or 16 or 32 or 64 or 128), the result should be zero (i.e. 0 in this case) and the formula should not be executed. Right ?

If I "force" the condition to 1, the formula works as expected, so I'm pretty sure I've a mistake with the "AND" in the condition, maybe a syntax problem ?

I wonder if it is allowed to have an "AND" in the condition, at all ?
According to the doc, yes, as long as the result is of type boolean 0-non zero.
NB: the "AND" in the formula part of the expression works fine.

Any hint ?

[MarcNaroska]

Hey Raymond!

I had this problem before while developing my Rolladen-Baustein.
The solution which worked for me is:
"((EN[9] & 1)==1)" to test if bit 1 is set
"((EN[9] & 2)==2)" to test if bit 2 is set
"((EN[9] & 4)==4)" to test if bit 4 is set
and so on.

That worked for me without any problems after I first tried it in the same way as you did...

[Warichet]

The solution which worked for me is:
"((EN[9] & 1)==1)" to test if bit 1 is set
"((EN[9] & 2)==2)" to test if bit 2 is set
"((EN[9] & 4)==4)" to test if bit 4 is set

Hé, hé
Thank for the tip . Will try it asap

That worked for me without any problems after I first tried it in the same way as you did...

The same cause often yields the same result

Another question, about the variables EN and EC

EN Array The current value of the inputs.
EC Array of Boolean
  1 == A telegramm has been received at the input.

I don't see the subtle difference.
A word of explanation is welcome.

Thank you very much.

[Taxus]

Hi Raymond,

EC[m] tells you, that the logic module has been triggered by a telegramm arriving at pin number m, and
EN[m] tells you the value of the telegramm.

Greetinx!

[Warichet]

EC[m] tells you, that the logic module has been triggered by a telegramm arriving at pin number m, and
EN[m] tells you the value of the telegramm.

ûh
Still confused
Can you tell me when to use the one or the other ?

Maybe it's more appropriate to use EC[m] for variable inputs ? as it does 2 things at a time: it says:
1) a telegramm has arrived at pin number m
2) the value of that telegramm

Is that correct ?

[MatthiasS]

No, it is not.

Example:

EC[1]| EN[2] + en[3] | |..|4

This says:

If you have a telegramm on pin 1 (maybe a minute trigger), then send the sum of EN 2 and EN 3 to outpu no. 4

EC does not contain the value of the input pin! It only says that there was a new telgramm on that input pin.

[Warichet]

EC does not contain the value of the input pin! It only says that there was a new telgramm on that input pin.

Thank you very much.
By looking at the existing examples, I see that EC is often used in the conditional part of the expression.

PS:
Isn't the behaviour of the "AND" in the condition, a bit disturbing ?

[Warichet]

Hi Marc,

The solution which worked for me is:
"((EN[9] & 1)==1)" to test if bit 1 is set

I'm unable to make these lines work

5012|0|"((EN[9] & 1)==1)"|"EN[1]"|""|1|0|0|0
5012|0|"((EN[9] & 2)==2)"|"EN[2]"|""|2|0|0|0

Seems to be the same as yours, at least about the condition.
Again, when I force the condition, like this,

5012|0|""|"EN[1]"|""|1|0|0|0

it works. So, it has to do with the condition.
I guess I missed something.
Any clue ?

[Taxus]

Sorry for asking that - you have at least 9 input-pins?

[Taxus]

To your primary question: please use

5012|0|"((int(EN[9]) & 1)==1)"|"EN[1]"|""|1|0|0|0

[makki]

And another thing, in the unlikely case you don't do this already: install python idle shell for testing. I made myself a simple textfile to paste values for EN[x] and EC[x] for testing..

Makki

[Warichet]

you have at least 9 input-pins?

Yes. Anyway, the Experte would complain if the number of declared inputs doesn't match.
I want to translate a status byte into the clear text equivalent of each status bit set to 1 (see picture below).
At input Pin 9, I get the unknown status, Byte, 0-255
At input Pins 1-8, I fil-in the meaning of each bit, static 14Byte text
At output Pins 1-8, I collect the clear text, according to the bits set in the status byte. Rather simple, no ?

5012|0|"((int(EN[9]) & 1)==1)"|"EN[1]"|""|1|0|0|0

I thought about it for a while, but I'm pretty sure it's an integer. Maybe I should cast it to force the type integer ? But why ? it has been declared as type integer.

in the unlikely case you don't do this already:

Bingo !

install python idle shell for testing.

Sounds very interesting, this tool for chasing the
Maybe a pointer to it ?
I was already looking for a tools to easy a bit the Python writing, didn't find any compatible with the situation at hand.

Thank you.

[Warichet]

please use

5012|0|"((int(EN[9]) & 1)==1)"|"EN[1]"|""|1|0|0|0

Mmm, you are right.
It works
Still confused, why casting an integer that is already declared as an integer, 0-255 ?
I guess this is a lesson from experience ?

Thank you

[MarcNaroska]

Hey Raymond!

As far as I know you only define inputs and outputs of a Baustein as numerical or alphanumerical. Maybe all numerical variables are internally declared as double...

I'm sorry for my last post where I forgot the INT(), but I didn't had a look into my Baustein where I used this and wrote it just from memory...

Nevertheless, as long as it works now, don't worry about the why...

[Warichet]

As far as I know you only define inputs and outputs of a Baustein as numerical or alphanumerical.

That's perfectly correct
But I was referring to the
Experte/Stammdaten/Kommunikationsobjekte/Intern
and there, the "Status byte" is defined as "8-Bit (0..255/EIS 2,6)". Isn't that an integer ?. Also, the title of the line is "Datentyp", sooo

I'm sorry for my last post where I forgot the INT()

No problem . Thank you for the kind help, anyway.

Nevertheless, as long as it works now, don't worry about the why...

Oh well, I've a strong tendency to worry a bit and I'm willing to gain some experience with this #@$& stuff.
Someone said:

Experience is the sum of all errors

Well, I'm collecting a terrific amount of experience these days