Created Date: August 24,2017

Created by: CaerYnArfon

Well having had one problem solved by this forum was hoping you could shed some light on the following.

I need to calculate a value from the following equation RPM = Speed/pi x Diameter.

So typical values are RPM = 300/3.142 * 450

300 and 450 are both at V memory addresses.

I then need to take that result 0.2122.... 4 decimal places is enough

Divide it by 0.1203 and multiply the result by 415 which gives us 732.142... I then need to pass that Integer only value (732) to

The V460 address which is the F0-2AD2DA-2 slot 3 Port 1 Analogue output which gives me a voltage of approx 1.9 volts. (controlling speed)

However no matter what Math ibox i use the results are crazy they bear no resemblance to the figures above.

I assume its all to do with what kind of data type we are using? Decimal. Binary BCD whatever...

But how do I know?

Then how do I know what to convert to and back again etc.

Also, how come at any point in the ladder, I can't just OUT a value to V460 (red dot) but I can OUTD to V460 the value is the same in both cases and as a decimal value from 0 - 4150

Any ideas.

I know this is probably fundamental DL06 programming but I 've come in to this cold from a general electronics and programming in VB and C background and haven't had any formal training whatsoever so kind of stabbing in the dark... :-(

Thanks guys.

Created Date: August 24,2017

Created by: plcnut

Also, how come at any point in the ladder, I can't just OUT a value to V460 (red dot) but I can OUTD to V460 the value is the same in both cases and as a decimal value from 0 - 4150

OUT defaults to an OUT coil.

If you type the / (Forward slash) at any time that an OUT instruction is being edited, then you will get the input for an OUT Box.

Created Date: August 24,2017

Created by: Mike Nash

I need to calculate a value from the following equation RPM = Speed/pi x Diameter.

So typical values are RPM = 300/3.142 * 450

300 and 450 are both at V memory addresses.

I then need to take that result 0.2122.... 4 decimal places is enough

Your equation is wrong to start with. You mean 300/(3.142 * 450) if you really want 0.2122.

Next, if you want REAL results, all of your Vmem values must the REAL before you use the MATHR IBox.

A REAL number requires an OUTD because it is a double. I don't know which instruction you are using though so I can't check on my D0-06.

Created Date: August 24,2017

Created by: bcarlton

Determining data type - open a dataview window. Insert the variable location. Change the view types for that item as needed until it reads correctly.

If the data type is 'decimal ' then convert to REAL using the BTOR instruction

If the data type is BCD (view is BCD/Hex) then convert to REAL using BIN then BTOR.