Help to find variable value

Hello Mates,

First time I'm in touch with the TI505, migrating to a S7 1500. 

I'm in trouble to find the value of some variables wich in the loop have no writes, just reads. 

Like V401, V320, V342, V315 and some others, could someone please help identify they in the program (attached)?

V401 is used in calculations starting on address 2107  and following.

it holds a value of 65535, it's used to do some scaling calculation on analog inputs.

V342  the same, it holds a value of 40.

V320  the same, used ladder address 3112,   holds a value of 320

V315  the same, used in ladder address 2162, holds a value of 15

all these V-memories are used as constants (K-memory could have been used instead)

the values are written once in the V-memories via a chart. That is why you don't find any assignment of these values in the program itself.

This is more or less a dangerous programming technique. If someone erases the value in the V-memory inadvertently suddenly the program doesn't work any more. Better would have been to assign these values to the V-memories in the ladder program.

Hope this helps,

Rgds,

Carlo

Hello, 

thanks by you reply, were could I'see this V-memory loads?

I agree with you, store the program constants in memory dependent variables are dangerous.

Also, for the analog scale, why multiply the input word (WX3) by 65535, the would overflow, not?

You can see the values of the V-Memories in a Tisoft Chart.

i have no idea why they are multiplying WX3 by 65535, you need to understand the application for that.

the result of the multiplication is stored in a double word - 32 bit integer - V672 & V673, so there is no overflow.

Regards,

C.