Value Scaling

Nice piece of software, simple to use and easy to learn.
I have a Modbus RTU slave connection which is polling nicely and putting the decimal values on the graphical interface.

What I would like to do is scale those Modbus values to show 0-100% instead of 16384 to 49152 as recorded from the device.

I have tried putting in a computable Simulator variable with some code to do it, however it doesn't seem to be able to reference a MODBUS variable from the simulator plugin.

Has anyone else done this before?
I am about to delve into the scripting to see if there is another way.

  • +1
  • 23 June 2011, 21:49
  • RFEE
  • 2


Hello dear friends. Im trying this software but i have some questions. I hope somebody culd help me. I designed a SCADA visualization for temperatures monitoring. But the problem i have is the computer was broken. I need to use my development in a new computer. Well i saved a baackup of the files but the problem is that apparently i can not just change the original file from 1 computer to another. Because when try to open it a warning error brings up to the screen. I dont know whats going on. Sorry for my english. Thanks

Connecting to MODBUS PLC

MODBUS Plugin Configuration and test


MODBUS is an application layer messaging protocol, positioned at level 7 of the OSI model, that provides client/server communication between devices connected on different types of buses or networks.
It is currently implemented using:
TCP/IP over Ethernet at a reserved system port 502 on the TCP/IP stack
Asynchronous serial transmission
MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs.

( Read more )

Collective blogs.

Guys. I had move your posts from your personal blogs to collective «Help» blog, you can see a collective blogs names at bottom right of the page. Pls select the most appropriate blog when you post new topic. For do this you should be joined to appropriate blog. Look to the picture.

Also you can subscribe on new topics in joined blogs and new comments. Go to «site settings» like showed in pict.

BCD Data type for Modbus

I would like to see a BCD Data type when creating a Modbus Variable. Many of the PLC's I work with have data in BCD format. This will make it much easier to attach graphics if you don't need to do the conversion in code.

Keep up the good work. I am looking forward to seeing some of the bugs fixed. I lost a few tinkering projects when the designer crashed and would no longer load the project. Once it is running and my scripting is de-bugged it seems to be pretty stable.
  • +1
  • 23 December 2010, 05:12
  • SEKen
  • 2

Problems with programs

I am wanting to develop an application with the Free Scada,
I'm creating simple programs, but I can not call buttons with actions…
I am also wanting to create a tutorial for setting up the Free SCADA
I need help from someone…

Adds up the possibility to use the slave_ID=255

Hi Alex,

It might be good to be able to use the value 255 as slave_ID.


Carlos Enrique Liendo

Your suggestions.

We are come back to active development, we need your suggestions for a fuser improovements for FreeSCADA. Post your suggestions in this blog.

For do this — push button «Write» situated in top left corner of page(while you logged in) — you will see the form for creating new post, select blog «Development» and write your post.

Regards Alex.

Users Manual

Hi I want to know if there are a manual or help for developers that use the FreeSCADA?

New Site

We are launched new site. This is social blog engine. All news will be published in «News» blog. Releases will publish in «Release» blog. «Tuttorials» for tuttorials :) You can register and ask your questions in «Help» blog. Make your suggestions in «Development» blog. All discussions will be in comments threads for published topic.
For publishing topic you need to login and press button «Write» in top-left coner. After this select blog in which you whant to post your topic and thats is.
Ohh users have a rating, any user after register take zerro rating and can write posts only in Development and Help blogs. Rating will increase in acording with user activity inside comunity, when user will exceed presetted treshold it will takes rights for posting in other blogs.
PS. Old site can be found there: