在制造业的任何人都可以证明,典型的plant floor is comprised of devices from an array of vendors. It’s simply the real world result of the varied features available on automation products coupled with the wide-ranging preferences of those in charge of the buying decision when devices are purchased.
The problem has been in making them all these devices work together.
To help ease this interoperability hurdle, the Machinery Initiative—launched bySercos International(www.sercos.com),ODVA(www.odva.org),andOPC Foundation(www.opcfoundation.org)in April 2011— was designed to find ways to make interoperability easier for users.
The first step taken by the initiative has been to focus on how to implement a joint network infrastructure in which the different network protocols can co-exist while also allowing for devices from different manufacturers to be operated in unison. Thanks to the unifying force of Ethernet’s physical and data layers, the Machinery Initiative has been able to announce the first practical results of its efforts just a year after its formation.
At Hannover Fair 2012, the Machinery Initiative announced that because the “infrastructure required for EtherNet/IP and Sercos III includes the physical and data link layers of Ethernet, Sercos telegrams, CIP messages and TCP/IP messages can coexist within a network without requiring additional cables. To keep the cyclical and clocked communication of Sercos III intact, the CIP messages and TCP/IP messages are transmitted in the Unified Communication Channel (UCC).”
Ultimately, this means that Sercos III devices, EtherNet/IP devices, as well as other Ethernet devices can coexist in a joint network infrastructure in a machine or system. Furthermore, existing Sercos III and EtherNet/IP specifications do not have to be modified because the communication mechanisms have already been integrated in the Sercos III transmission process.
According to the Machinery Initiative, an implementation guide that describes the planning and set-up of such multi-protocol networks should be available in late 2012, with initial prototypes to be presented at the SPS/IPC/Drives 2012 show in Nuremberg, Germany in November 2012.
