| Name: LP8x81|
Start: November 2009
Members: Roman Savochenko
Translator: Maxim Lysenko
Description: The project is devoted to the creation of runtime of the PLC LP-8x81 of the ICP DAS company based on the OpenSCADA.
Industrial controllers of the LP-8x81 family of ICP DAS company is the first product of the LinPAC series, which is built on the x86-compatible processor, the previous controllers of this family were based on the ARM processor. In addition to the x86 processors these controllers have significant resources of memory and disk space. All this allows to consider the controllers as the first candidate of the ICP DAS products for adaptation of the OpenSCADA as their runtime.
The reason for adapting OpenSCADA as runtime of the controllers of LP-8x81 family was the need for creation of the automatic control system (ACS) of the ball mill for the grinding of coal on the heat electropower station. The peculiarity of this process (TP) is the presence of specific requirements for the resources and functions of the controller with the small amount of parameters at the same time. Also the key factor was the limited funding. All these requirements are satisfied by the controllers of LP-8x81 family:
The aim of this project was to create the runtime based on the OpenSCADA, as well as the firmware with Linux and OpenSCADA for the controllers of this family. There are following requirements for runtime and firmware:
PLC (Fig. 1) is structurally made in a modular manner, where the modules are installed in the rack. Rack is combined with a processor module and can be 0, 3 or 7 slots for expansion modules. Expansion modules can be of two types, namely: modules of parallel and serial bus. Modules of the parallel bus (I-8x) are fast. Modules of serial bus (I-87x) are installed on the bus RS-485 interface and operate at the speed of 115000 bps over the DCON protocol. In addition to modules directly in the rack the controller can be expanded with additional racks with modules on the serial bus (I-87x) through the serial interface of the processor.
Processor of the controller has the following specifications:
|CPU||AMD LX800 processor (32-bit, 500 MHz)|
|System memory||1 GB RAM|
|SRAM with dual power from the battery||512 КБ (with storage for 5 years)|
|Flash||4 GB as IDE Master; Read: 8 MB/s; Write: 4 MB/s|
|EEPROM|| 16 KB|
Data storage: 40 years; 1,000,000 cycles of erase/write.
|CF card||8 ГБ (support up to 32 GB); Read: 29 MB/s; Write: 19, 13(233x) MB/s|
|64-bit Serial Number of the Device||Available|
|Double Watchdog timer||Available|
|VGA||640 x 480 ~ 1024 x 768|
|Ethernet ports||RJ-45 x 2, 10/100 Base-TX Ethernet Controller (Auto-alignment, auto MDI/MDI-X, LED indicator)|
|USB 1.1 (host)||2|
|COM1||Internal communication with the modules I-87K in the slots|
|COM2||RS-232 (RxD, TxD и GND); Not isolated|
|COM3||RS-485 D2+,D2-;self-tuning of the ASIC inside|
|COM4||RS-232/RS-485 (RxD, TxD, CTS, RTS и GND for RS-232, Data+ and Data- for RS-485); Not isolated|
|COM5||RS-232 (RxD, TxD, CTS, RTS, DSR, DTR, CD, RI and GND); Not isolated|
|Working temperature||-25 ~ +75 °C|
The original software is the Linux distribution with the graphical environment Gnome and the drivers installed for the specialized hardware. In addition, the environment includes the "C" compiler with LinPAC SDK, as well as the interpreter of Perl.
Given that the source distribution is unknown, which is used by the supplier, and as the consequence the ability to install additional software is not prescribed, then using of this environment as it is, firstly, difficult, and secondly, not comparable with the available hardware resources. Besides the original Linux 2.6.18 kernel is far from our requirements.
For these main reasons it was decided to create an entirely new program environment. The basis of this software is ALTLinux 5.1, the Linux kernel 2.6.29-rt-up and OpenSCADA 0.6.4.2. The selected kernel satisfies all requirements, and distribution ALTLinux 5.1 allows to build compact firmwares for the necessary requirements.
Choose of the new environment has put the fact that, there is no source code for the specific hardware driver of the vendor. This problem was solved in conjunction with the developers of the original software environment, which have agreed to adapt and build their own driver under the right Linux kernel. Archives of these modules are available here.
To implement the support of controllers LP-8x81 series equipment and modules of I-8000 series it was created the module DAQ.ICP_DAS for the OpenSCADA system. The module provides the OpenSCADA system with support of various equipment from ICP DAS through company's API library libi8k.a.
Firmware of software was created in accordance with the instruction here. In addition to the standard materials the package was created with the files necessary for the Controller LP-8x81 - kernel-modules-icp-rt-up-1.0.0-alt1.2.src.rpm. In addition the profile of the firmwares' building was adapted for the building for LP-8x81.
In the process of software testing, it was found that the standard network controller's driver "via-rhine" is not working correctly: there is the significant speed decreasing of the network after normal working in the period from days to weeks. The problem was solved by the building the driver "rhinefet" from VIA.
The firmware build for LP-8x81 was eventually grounded on packages base of distributive "ALTLinux T6" with saving Linux kernel 2.6.29-rt-up, and this allow:
As the result it has been obtained and put into operation the firmware of software which satisfies all the requirements. Currently, this software works on the three controllers LP-8781 and serves as: