A soft PLC that is not so soft
February 2003
PLCs, DCSs & Controllers
The subject of soft PLCs in the automation and control industry usually raises, or lowers a few eyebrows, depending on what the particular eyes have seen happen with soft PLCs. The one lobby claims that soft PLC is the only way to do large scale PLC automation these days, especially in conjunction with scada and other third party software that can directly communicate with the PLC within the PC.
The anti-lobbyists will point out the particularly undesirable reliance of the soft PLC on the stability of the PC, specifically the operating system (and there are apparently some not so stable ones out there). Is there a solution? Could one have the great features a soft PLC has to offer without the risk of the whole plant going down at the first 'fatal exception' error?
Bosch Automation Technology believes it has found just the right solution. It is a middle path of sorts, a soft PLC with a hard shell, so to say. It is a PCI card, with a Unix processor onboard that runs VxWorks, looking like a simple network card to Windows, but actually using the PC's processor and controlling the PC's resources. VxWorks is a widely adopted realtime operating system (RTOS) in the embedded industry, see www.windriver.com/products/vxworks5/#
This means that even in the case of a total breakdown of Windows NT, the safety-relevant control function remains fully operational. In addition, the PCL incorporates such PLC features as Watchdog, remnant data areas, forcing and peripheral monitoring, features which up to now were restricted to the classical PLC.
OPC, Profibus-DP, InterBus-S, CANopen, DeviceNet and ethernet TCP/IP are all possible forms of network and inter software communication. The PCL, the software-PLC from Bosch, combines the reliability and functionality of the PLC with the flexibility and open characteristics of the PC. PCL can also be programmed using the high-level language C for special assignments, such as process data processing (PDP). With up to 8192 byte I/O, 60 ms/1 k instructions processing speed and 16 KB of flags, its manufacturers say that it is unlikely that any user would reach these limits.
For more information contact Pascal Schmitz, Flexible Electronic Systems, 082 506 8312, [email protected]
Further reading:
All eyes on the modern DCS platform
Schneider Electric South Africa
PLCs, DCSs & Controllers
Modernised DCS platforms are no longer confined to hardware-dependent architectures. These systems have evolved to combine the strengths of both PLCs and DCS while adding capabilities that make them more open, resilient and collaborative.
Read more...
Automation solution for waste management at incineration facility
PLCs, DCSs & Controllers
Valmet is to deliver an automation system to Seongnam City’s incineration facility currently under construction in South Korea. By leveraging intelligent automation, the plant will optimise energy production, minimise emissions and deliver efficient, consistent performance throughout its entire lifecycle.
Read more...
Valmet’s supplies DCS to Europe’s largest electric boiler plant
Valmet South Africa
PLCs, DCSs & Controllers
Valmet will supply an automation system to Helen’s Hanasaari electric boiler plant and a thermal accumulator being built in Helsinki, Finland. Once completed, it will be Europe’s largest electric boiler plant.
Read more...
Technology blueprint paves way for e-methanol fuel expansion
Schneider Electric South Africa
PLCs, DCSs & Controllers
Schneider Electric has delivered the technology stack behind European Energy’s Kassø Power-to-Xfacility, the world’s first commercially viable e-methanol plant.
Read more...
PCS Global delivers turnkey MCC installation in Botswana
PCS Global
Editor's Choice PLCs, DCSs & Controllers
PCS Global is delivering a turnkey containerised MCC installation for a major copper mining operation in Northwest Botswana.
Read more...
New energy-efficient evaporation line for dissolving pulp production
Valmet South Africa
PLCs, DCSs & Controllers
Valmet will deliver a new evaporation line to Altri Biotek mill in Portugal. This delivery is part of Altri’s €75 million project to convert the Biotek mill to produce dissolving pulp for the textile industry.
Read more...
Valmet modernises turbine automation
Valmet South Africa
PLCs, DCSs & Controllers
Valmet has received an order to deliver a comprehensive replacement of plant DCS and turbine control systems at Ennatuurlijk’s combined cycle power plant in the Netherlands.
Read more...
Hybrid DCS for an evolving industrial landscape
Schneider Electric South Africa
PLCs, DCSs & Controllers
Today’s industrial automation continues to evolve at a blistering speed, which means traditional DCSs have to keep up to ensure continuous integration into modern, digital infrastructure.
Read more...
IIoT controller for the field and control cabinet
ifm - South Africa
PLCs, DCSs & Controllers
The IIoT controller from ifm is a powerful, communicative and flexible PLC solution in machine and plant digitalisation.
Read more...
Bringing the benefits of Ethernet to hazardous industrial environments
ABB South Africa
PLCs, DCSs & Controllers
Christian Johansson, global product manager for ABB Process Automation explains how Ethernet-APL lets plant owners unlock more value from their process data, optimise performance and promote safer operations.
Read more...
printer friendly version