Posted to News on 19th Feb 2011, 16:40
Inverters add PLC capability to PID, servo and position control
Nord Drivesystems is extending its range of SK 500E series compact frequency inverters for control cabinet installation, adding the top-of-the-line model SK 540E that features integrated basic PLC functionality. Without the support of an external controller, the cost-effective inverter is able to control many demanding applications with sequences and links to counters, comparators and flags; it is said to be easily programmed in accordance with the industry-standard IEC 61131-3 using the PC-based NordCon tool.
The PLC functions provide control for up to eight digital inputs, three digital outputs, two relays, two analogue inputs and one analogue output. If required, more I/O extension modules may be added. The new inverter may be used for applications such as the integration of monitoring functions into pump drives, enabling them to autonomously react to flow rate fluctuations. All operating data can also be transferred to higher-level controls with the SK 540E featuring interfaces for standard fieldbus systems.
Even without an integrated PLC, SK 500E series inverters support a wide range of industrial applications through integrated functions including PID control, a servo mode that ensures full torque at standstill, and absolute and relative positioning with the Posicon module.
SK 500E inverters are available in seven sizes and cover motor ratings between 0.25 and 37kW. The new SK 540E will shortly be available for performances up to 7.5kW, and versions from 11 to 37kW are in development.
