Looking for a soft PLC

Hello,

I would like to buy (or not) a PLC in "C source file" packaging, with a HMI
running over a PC, and complying actual standards (IEC 611-31)

Is there any alternative to CoDeSys ?

Thanks.

Just in case : ... to buy (or not) ...... means "freeware" for example !
But I'm also interested in costly PLCs !!

Thanks again.

Go to control.ccm. Click the LinuxPLC icon. There is a GNU licenced soft PLC written in C. If you are really into that kind of stuff, download the tarball and compile it. I have looked at the source code. Its an interesting project. They still have a ways to go to become full featured, but all the basic stuff is there.

as far as i know ,this is possible with siemens

there is a seires other than s7 which can be programmed with c language , iam not very sure is it c7 or m7

Amr Hassan said:

as far as i know ,this is possible with siemens

there is a seires other than s7 which can be programmed with c language , iam not very sure is it c7 or m7

Click to expand...

The seires is M7, but you still need plc hardware. Another way of doing this is with siemens WinAC, their soft plc. You can purchase an option package WinAC ODK, in wich you can program functionblocks in C code. Pretty neat actually.

I could never understand why any one would, little alone, want to, program in C.

Could you explain why?

Sometimes, it is a customer requirment, but that really is not a good answer, or reason, as to why.

Casey, it entirely depends on what you want to do. Parsing a large text file is a pain in the rear in Ladder, do-able in VB, but a breeze in C. Writing a btree (for data access) in ladder would be impossible, difficult in basic, but its easy in C. A good PID controller is much simpler to write from scratch in C than it is to write from scratch in ladder. Single bit access comes easy in ladder, but in C you have to bitwise AND a word with a mask and then test its value. Ladder requires multiple memory store and fetch operations just to do a simple equation, but C easily handles complex equations all in the stack without lots of intermediate storage steps.

Virtually any modern computer application was probably written in multiple languages.

Alaric:

Perhaps they did too good of a job indoctrinating me.

Maybe, I'm just too old fashioned.

regards.....casey

Excellent points, Alaric.


One thing I've found much easier with ladder vs vb programming is timers. I find this much more difficult on anything longer than a minute or so...
-Mike