OPC DX: The show must go on
Hannover, Germany - The OPC Foundation's DX protocol, announced at the ISA conference in Houston in September 2001, didn't quite make its formal debut at Hannover as planned.
Karl Deiretsbacher, a Siemens A&D engineer, shows the OPC DX display.
Hannover, Germany - The OPC Foundation 's DX protocol, announced at the ISA conference in Houston in September 2001, didn't quite make its formal debut at Hannover as planned.
Hannover was to be the venue of the first DX prototypes, but technical snags prevented publication of the specification at its deadline in December 2001, so companies leading in the effort, such as Siemens, Phoenix, and Emerson, were not able to complete their demonstration products as planned.
The DX protocol is designed for "server-to-server" communication via Ethernet, as opposed to OPC DA, which is a "client-to-server" protocol. DX would allow, for example, PLCs of different manufacturers to communicate directly with one another, as long as they are connected together on the same Ethernet.
Helmut Gierse, president of Siemens A&D, said he regretted the delay but felt confident that his company would introduce its first DX products in the autumn of 2002. Siemens' original plan called for introduction of DX products in the summer of '02.
But as they say in the theatre business, "the show must go on," so in this spirit the OPC Foundation had a demonstration of the DX concept, with controllers from Siemens, Phoenix Contract, and Emerson communicating directly with one another.
However, Karl Deiretsbacher, a Siemens engineer assigned to the stand, admitted the demonstration was basically to show the DX concept, not the actual DX operation. PCs hidden behind the display area were taking care of protocol details that the controllers were not yet equipped to handle.
The first showing of OPC DX will likely be at SPS/IPC in Nürnberg in November, he said.
Control Engineering Daily News Desk
Michael Babb, editor, Control Engineering-Europe