Posted to News on 10th Dec 2008, 14:40
Servo controllers gain new safety functions
ELAU, a Schneider Electric company, is introducing a new safety product for the functions Safe Stop 1 (SS1) and Safely Limited Speed (SLS) for its MC-4 servo controllers. Available directly from ELAU, the required control unit is claimed to exceed the performance achieved by devices currently on the market.
MC-4 series standard servo amplifiers already provide the safety function Safe Torque Off; however, commercially available control units were needed where applications required a functionality upgrade to SLS and SS1.
Together with BBH, ELAU has enhanced a product from the portfolio of the Weiden-based safety specialist and has included it in its own product range: the safety control unit SMX 11 controls one axis, the SMX 12 device controls one or two axes. Interface modules for CAN and Profibus DP, as well as optional I/O, are available for both control devices. ELAU provides the control units with application recommendations. The safety functions are compliant with the requirements for SIL2 and PL d/Category 3.
Aside from the standard function Safe Torque Off, the combination of MC-4 servo amplifier and SMX 11 and SMX 12 now enables the implementation of the safety functions SS1 with deceleration rate, SLS and Zero Speed Monitoring for the servo drives of the SH and SM series. Compared with the existing time delay monitoring while decelerating, the explicit deceleration rate monitoring for the function SS1 is a significant upgrade.
With the component's reaction time of 4ms the servo amplifier will react to the trigger event within less than 20ms. If necessary, several protective circuits can be monitored if the Emergency Stop function and the guard doors control different drives. The safety control units are also cost-effective. The SMX 11 and SMX 12 units are available from ELAU as of now.
