MOTION CONTROL: In order to better help machine builders and manufacturers streamline safety systems with simple safety I/O terminals, Beckhoff Automation has introduced TwinSAFE Terminals for the EtherCAT® I/O system. Rated for SIL 3 and conforming to IEC 61508 and EN ISO 13849-1 PL e, TwinSAFE Terminals for EtherCAT are certified for use throughout North America.
These new safety terminals for the EtherCAT I/O system fully utilize the high performance of EtherCAT - the EL6900 safety PLC terminal can integrate up to 128 4-channel safety terminals (512 safety devices) and is capable of processing 256 safety-relevant function blocks. The safety function blocks integrated into the EL6900 Safety PLC are configured according to each unique application. In this way, safety functions can be easily programmed such as emergency stop, safety door monitoring, two-hand control, serial/parallel muting, timers and latches. Even a connection shutdown function can be established so interchangeable sections of equipment with safety terminals installed can be removed from the machine without causing safety system errors.
Systems can be expanded with additional EL6900 Safety PLCs as necessary. In this way, the safety-relevant control tasks for machines and plants can be implemented locally or centrally according to the application. The 24 V DC digital input terminals (EL1904) and 24 V DC digital output terminals (EL2902: 2.3 A and EL2904: 0.5 A) are available for connecting safety sensors or actuators. The TwinSAFE Terminals can be installed in any position in the terminal system and in distributed I/O systems. The EL6900 Safety PLC can also be used as a safety controller for AX5000 Servo Drives from Beckhoff, which use EtherCAT as a motion bus.
Safety over EtherCATTM permits the integration of safety devices into a control system without requiring a stand-alone safety PLC or segregated safety network. Safety data is handled via a “black channel” passed over a standard Ethernet cable. Integrated into a standard terminal block housing, this new safety solution is exceptionally compact, offering the highest flexibility via nearly limitless positioning within EtherCAT Terminal systems. Standard EtherCAT I/O terminals can be intermixed into the same node alongside the safety terminals.
TwinSAFE - the proven safety solution from Beckhoff - has already been successfully integrated into the company’s original Bus Terminal I/O system (K-bus) and is in use worldwide in a broad range of applications. With the integration of TwinSAFE technology into the EtherCAT Terminal system (E-bus), the high performance of EtherCAT, with its ultra fast communication and enhanced diagnostics, is now available for safety technology.
Safety applications can be created optionally by means of simple configuration in TwinCAT software from Beckhoff in System Manager or - in the case of more complex applications - programmed using TwinCAT PLC (IEC 61131-3). All safety-relevant parameters of the Safety PLC are available in TwinCAT and can be used in the standard controller. Typical drive functions can also be selected and linked very simply.
In the case of possible required service, the EL6900 Safety PLC terminal can be replaced quickly and easily without the program having to be explicitly reloaded and verified. The configuration is automatically loaded and verified by the system so trouble-prone removable media can now be dispensed with. The manual loading or saving of the project is also no longer necessary in the case of service.
A further highlight is the integration of a tool in TwinCAT for calculating and determining the SIL or PL according to EN IEC 62601 and EN ISO 13849-1. The previous complicated analysis of the safety application and the transfer of this information to an additional tool are no longer required. This can lead to significant work reductions and cost savings.
-Edited by Kelsey Anderson