[A guest post from James Powell, author of Catching the Process Fieldbus, reviewed here.]
“The times, they are a-changin’”. Bob Dylan wrote these words decades ago (and about a very different topic!), but when I look at the Profibus PA market today, this song immediately pops into my head.
Last year at this time, there were just two manufacturers that made DP/PA Link/couplers: Siemens and Pepperl+Fuchs. It had been that way for over a decade: some innovations occurring, but still just two companies. Now, there are four companies – and the two newcomers are innovating like crazy.
Siemens offered several related solutions: a simple coupler that just did a physical translation; a Link module that created a sub network; and full ring redundancy with some basic diagnostics.
Pepperl+Fuchs offered a similar range of solutions with some variants such as invisible couplers even when connected to 12 Megabit DP. Their redundancy solution was power-based as opposed to ring. Also, they innovated great physical layer testing with their built-in advanced diagnostic module.
Both companies have had a number of great innovations, but now with the two newcomers, the options for end users have increased significantly.
ifak system out of Germany has made a very compact and cost-effective PA module which plugs into an Ethernet head module that supports either PROFINET or Modbus TCP. It is easy to use and easy to integrate. It also supports transparency down to the instrument via FDT/DTM technology. Profibus PA bus diagnostics are being added.
Procentec out of the Netherlands has released a PA coupler for their COMbrick line. COMbrick is a module repeater/gateway technology with integrated diagnostics. I find it hard to describe this product in a few words, but like its ifak counterpart, it is dripping with innovation and new functions are being added. Currently it supports DP to PA coupler functionality with ProfiTrace diagnostics.
What does this mean for the end users? In short: more choice – never a bad thing in the marketplace.