S7 compare different data types 314cpu

Ned_Flanders

Member
Join Date
Oct 2008
Location
In hiding, England
Posts
535
I want to compare an actual speed value (PIQ "Real" data type) from an analogue input, to the setpoint (0 - 100%)that is input on the HMI to the machine "Int" data type.

To get from percent to rev/min is straight forwards - multiply by 23 but I can't see a neat/simple way to do the actual comparison.

Any suggestions?
 
Hi Markie.

I dont know about "PIQ" and REAL datatype for an analog input.

The input from an analog input in S7 is usually a PIW scaled to 0-27568.
It is quite common to scale this raw signal to engineering values by means of FC125 "SCALE" for example. This converts the raw analog INT input to a scaled REAL value.

I recommend to use REALs throughout, it uses a little more memory and takes a little more CPU time to execute, but trying to use INTs in stead requires cumbersome shifting of decimals and checking of limits.
Using REALs throughout makes coding, and subsequent troubleshooting so much easier.
 

Similar Topics

Hi all, I've collected some data from one of the flour mixer machine from our customer last week using a powermonitor 3000 M4. But I do not...
Replies
17
Views
5,440
Help please. Im new to Omron and have a machine down. I have a compare = for barcode label scan. I've attached two pics. On the Mnemonics you can...
Replies
4
Views
600
Hi everyone! Accidentally closed it and it wont appear again. Checked and unchecked the option and seem to make no difference. Running v7.10.00...
Replies
16
Views
1,814
I'm working on an array that contains a UDT of 5 Items Array[4] DataType[0] - Part 1 - Part 2 - Part 3 - Part 4...
Replies
1
Views
813
Hi. I have 2 files where I would like to see the ladder logic differences (similar to the Rockwell compare function). I am using TISoft Siemens...
Replies
1
Views
1,228
Back
Top Bottom