Sigmatek expands controller functions to take on safety

11 March 2009

At the SPS/IPC/Drives show Thomas Cord (photo) was showing off Sigmatek’s new safety controller, which is integrated with the C-DIAS programmable controller.

Thomas Cord

At the same time, Sigmatek has embedded safety functions into the DIAS-drives which eliminate mechanical operations that previous drives systems would have to perform when the drive would go into controlled shutdown mode. The two most common functions are Safe Stop or Safe Torque Off; additional functions such as Safe Operating Stop, Safety Limited Speed, or Safety Limited Torque are provided through an expansion module.

To demonstrate the system integration, the safety controller itself and some optional I/O modules (which are all coloured yellow and end with the number 011) were shown mounted along with the standard white PLC modules in the C-DIAS rack.

The main safety CPU is the CSCP 011, which has four safe inputs and two safe outputs. For simple applications, it may be the only module required. It runs an application program that monitors the safety signals from the drive and any other safety devices that may be optionally connected to it. The CSCP handles only the safety signals; the regular bus traffic goes to the main controller of the system.

If the application is more complex and needs to have more I/O, users can add the CSDI 011 module with 18 safe inputs and 2 outputs and the CSTO 011 safety module with 8 safe outputs.

Mr. Cord says the beauty of the system is that no additional wiring is needed for communications, because both standard and safety signals and data are exchanged over the VARAN bus. VARAN is an Ethernet-based, ‘hard real time’ capable system.