iFix 5.1 - Difference in value between AO and AA block

[Heinz8]

Hello,
I have a problem with AO- and AA-Tags.
When I use for example the tag AO_Test with the address 200 and type the value 1,2 in, the AA-Tag AA_Test with the same address shows the value 1,22.

Do you have any idea why it is?

Thank you for your help!

 

[glennz]

Both blocks are using the same I/O Address of 200 (which is a Simulation address, if I recall correctly). So each block's output will represent the value of that address.

 

[TheWaterboy]

AA is used to monitor a tag and sound an alarm based on its own setpoints, AO is used to output a value.
You are feeding the AO into the AA and it sounds like that is just what you intended to do and its working as planned.

However 1,2 shouldn't be a valid value for an analog block unless your regional settings use a comma as a decimal.

 

[Heinz8]

Thank you for your answers.
Yes, in Germany we have a comma for decimal.
And my plan is that the incomming value in the AO block is the same like in the AA block with the same address. But there are always small deviations and I don't understand why.

 

[shanefaulkner]

Thank you for your answers.
Yes, in Germany we have a comma for decimal.
And my plan is that the incomming value in the AO block is the same like in the AA block with the same address. But there are always small deviations and I don't understand why.

Are the EGU high and low spans of the AO and AA blocks identical, with the same number of digits to the right of the comma?

 

[Heinz8]

Yes, the decimal places are the same.

 

[shanefaulkner]

Yes, the decimal places are the same.

How many decimal places do you have for these two tags?

One other thing I can think of that might be causing you issues: do you have smoothing turned on for the AA tag (it's on the advanced tab)?

 

[Heinz8]

I have set 2 decimal places. But even with 3 or 4 is the same problem. No, smoothing is not enabled.