stop rounding??

is there a way that i can stop all the rounding that is going on between plc and panelview?

i have a number thats lets say 8.82345 and all i want is the first number the 8. i want to take that number and display it on the panelview (600) if i use an interger it rounds 8.8 to 9. if i use the float and only try to display the first digit the panelview then rounds it also,

how can i get the 8 from 8.82345 to only be displayed on the panelview??

thanks guys!

Hello,

Normally a function named 'Trunc' (Truncate) will return just the part to the left of the decimal point. I do not know what the PanelView offers. Or do the Trunc in the PLC and put the result in an integer register.

For PLC/5, SLC500, Micrologix:

Subtract .5 from the float and store it in an integer location.

Eg

SUB 8.82345 .5 N7:0 - N7:0 will contain 8.
Sub 8.34202 .5 N7:0 - N7:0 will still contain 8.

For ControlLogix use Trunc.

Alaric said:

For PLC/5, SLC500, Micrologix:

Subtract .5 from the float and store it in an integer location.

Eg

SUB 8.82345 .5 N7:0 - N7:0 will contain 8.
Sub 8.34202 .5 N7:0 - N7:0 will still contain 8.

For ControlLogix use Trunc.

Click to expand...

Yep, what Alaric says. I've done that in several programs.

perfect thank you again!!

Alaric said:

For PLC/5, SLC500, Micrologix:

Subtract .5 from the float and store it in an integer location.

Eg

SUB 8.82345 .5 N7:0 - N7:0 will contain 8.
Sub 8.34202 .5 N7:0 - N7:0 will still contain 8.

For ControlLogix use Trunc.

Click to expand...

Definately use Truncate in Logix5000 controllers, don't try the maths trick above !

Logix5000 uses a different rounding algorithm from the normal "xxx.5 and above goes up".

xxx.5 is neither nearer the integer above or below, so to always round up is statistically unbalanced.

So they use the "Round-to-Even" method, any number ending in exactly xxx.5 will round to the nearest even number.

Examples....

1 / 2.0 = 0.5 will store 0 in an integer destination (0 is considered even)
3 / 2.0 = 1.5 ...........2
5 / 2.0 = 2.5 ...........2
7 / 2.0 = 3.5 ...........4
9 / 2.0 = 4.5 ...........4

etc.

Can anyone try this in SoftLogix for me ?

Alaric said:

For PLC/5, SLC500, Micrologix:

Subtract .5 from the float and store it in an integer location.

Eg

SUB 8.82345 .5 N7:0 - N7:0 will contain 8.
Sub 8.34202 .5 N7:0 - N7:0 will still contain 8.
....

Click to expand...

Will work correctly only for positive values.
For negative ones, 0.5 must be added, not subtracted.

The "normal" function for this is "floor".

Pego said:

The "normal" function for this is "floor".

Click to expand...

Only if your PLC has the function