PLCs Go From Soft to Web-Ready

The launch of version 2.0 of Kontron Modular Computers' SOPHisticated Internet Access web service software (SOPH.I.A) enables soft PLCs and web services to grow together in order to reduce software development costs and increase the value of the overall application. SOPH.I.A 2.0 enables a quick and easy introduction of web services to soft PLCs that are based on the CoDeSys Automation Alliance. These services range from web-based visualization and operation using alarm and disturbance reporting management via e-mail to alternative sourcing via e-procurement. This is achieved by enhancing the SOPH.I.A web service software with a transparent interface for data transfer to the soft PLC, so that reading and writing is secured in both directions. Kontron's first application specific web-ready PLC for the modular ThinkIO DIN rail PC has been implemented using Linux.

The link between the soft PLC runtime system and SOPH.I.A. is implemented directly using SOPH.I.A.'s data provider. SOPH.I.A user variables are created automatically after downloading the CoDeSys application. This is achieved using the CoDeSys file BOOT.SDB. These CoDeSys variables and addresses are automatically registered as Sophia variables. Data refreshing takes place periodically via the soft PLC and the scanning cycle can be configured as required. CoDeSys RETAIN variables and addresses are exchangeable, since the soft PLC developer can configure them in the soft PLC as well as in SOPH.I.A. This is particularly useful for commissioning during operation and for servicing. The entire user interaction can be implemented web based. Diverse help texts and safety mechanisms can make a soft PLC extremely easy to use and the perceived quality rating can be increased enormously by the appropriate corporate web designs.

Soft PLC applications are still written independently of SOPH.I.A. in the classic PLC programming environment according to IEC 61131 and all five programming languages. SOPH.I.A. is informed whenever a soft PLC application is downloaded to the target system. This allows SOPH.I.A. to automatically create a new data module and to begin the cyclic data exchange with the soft PLC's runtime environment in the specified clock rate, which can be configured as required.

SOH.I.A's soft PLC interface allows developers soft PLC developers to implement all conceivable web services in a single development environment: Web visualization of real time data, configuration routines, user administration, password assignment, SSL encryption, alarm management and escalation routines including for e-mail services are only a few of the diverse features of this integrated development and run time environment for SOPHisticated Internet Access = SOPH.I.A. The advantage for SPS developers is that they have a proven functional integrated solution that is prepared for all the eventualities of web-based industrial computing, which saves both time and cost.