- This topic has 8 replies, 4 participants and was last updated 9 years, 10 months ago da
.
-
Post
-
I saw in your last monthly bulletin the new programmable ARM9 CPU module in Linux. I am already using your system SlimLine based on ARM7 CPU, I wanted to know more about this new CPU family.
What does this CPU have more than the ARM7 I am using?
Is it compatible with the same I / O cards?Con la nuova ARM9 CPU (Linux) we wanted to increase the performance of our programmable system SlimLine. SlimLine is a line of industrial boards for automation, programmable according to the IEC 61131-3 standard using the development environment LogicLab (Provided free).
For some time our Customers have been asking us to open the system towards new communication protocols (Serial, CAN, Ethernet), towards disk management with more and more files and more and more space available, the possibility of developing increasingly complex calculation algorithms . Hence the need to create a faster CPU with greater availability of resources. It was decided to use a platform based on ARM9 and given its open source nature, the Linux operating system was chosen to create a new CPU module to complement the existing one.
The new module has same dimensions and same connections of the ARM7-based module, the only difference is the presence of an extra USB host connector on one side. Of course, it has faster processing speed and more memory space for both the program and the file system.
The extension modules of the family SlimLine are perfectly compatible with the new CPU module.
As far as programmability is concerned, as seen from the product page, there are two lines of identical modules from the hardware point of view.
Linux Open
Programmable with all development tools in the GNU linux world. It is possible to operate via an ethernet connection in SSH (Example Putty) with the standard Linux command interface. For development we provide a VMWare virtual machine already set up with Linux operating system and installed development tools. Special libraries provide access to our extension modules.Linux PLC
Programmable with LogicLab exactly like the current CPU module. On this platform it is possible to migrate all the programs currently already developed for the current module, with the possibility of increasing the size and complexity of the program. New functions and function blocks will gradually become available on this module.Could you please give me more information regarding the following questions, related to IEC 611131-3 programming which is what I am currently using.
Do you always work in bytes?
Does a declared bit always occupy the same memory area?
Should the modbus pointing from scada always make the same calculation to find the correct variable in the memory?
Are the contemporary connections increased?
Do you have functions like webserver?
Can the hot program be transferred without stopping the execution of the current one?
How large is the memory area?I state that the LinuxPLC version even if announced is not yet available, we have prototypes in tests at our laboratories and at some betatester customers. I try to give you information about the features that will surely be present in the final version.
IEC programming is standard so we will always have the same types of data, for the variable you indicate bit I think it refers to the BOOL type which still occupies a byte of memory.
The modbus pointing will certainly be the same, but we will have a larger memory area, the current DB100 (currently 4096 bytes) will certainly be greatly expanded. It will be combined with other memory areas allocated in other DBs.
We will certainly have more contemporary Modbus TCP / IP connections, compared to the 3 currently managed.
It is possible to transfer the program while hot, ie without stopping the program in progress. You can then change the program while the system is running the previous one without stopping.
For the WebServer function we certainly intend to activate it with the possibility of defining web pages that can be configured by the user, but this will come later.
I would like to better understand the differences between the LinuxPLC versions and the programmable version with LogicLab, will there be performance differences? Will there be different features between the two versions?
The two modules are perfectly identical from the hardware point of view, the version Linux Open it is programmed using classic development tools in C and / or C ++ languages (See post).
The Linux PLC has the program Run time for LogicLab and with the free development environment LogicLab it is possible to program using the 5 standard languages of the IEC 61131-3 standard. In this way it joins the previous ARM7 model by increasing performance and functionality.
The Linux PLC model includes a series of functions and function blocks already prepared to solve a wide range of problems as well as additional constantly evolving libraries. Among the most interesting libraries I remember the one for the support of the CAN Open protocol.
Yes, being able to execute both a task in PLC and programs written in C for Linux is one of the objectives. Unfortunately we have remained a bit stuck on PLC development because we have had problems with Real time libraries.
In order to perform PLC tasks in Linux environment it is necessary to make the operating system Real time and this means doing a big job of rewriting the device management drivers.
Meanwhile we have developed the compatible CoDeSys version of the CPU module SlimLine which is based on a real time operating system developed by Beck.
- You must be logged in to reply to this topic.