One of the reasons that many facilities do not approve the installation of repeaters on their industrial networks is because these installations all require power for the repeater element and unfortunately finding reliable power where and when you need it is not always a ‘sure thing’ and with the increased use of wireless access points throughout a facility the demand will do nothing but grow.
The good news is that at least two options to provide reliable UPS field power that I am aware of are now available.
Weidmueller have been offering their BBU (Battery Back Up Units) http://catalog.weidmueller.com/catalog/Start.do?localeId=en&ObjectID=9916280024 for a number of years however they have not yet integrated it into a solution so either you or your system integrator have to purchase the remaining pieces from them or your preferred supplier for those parts and assemble them in a suitable enclosure.
Phoenix Contact however has recently released an integrated solution complete with “local” USB interface you can use to monitor the operations. Their UPS-IQ technology http://www.phoenixcontact.ca/signal-level-matching/242_65994.htm provides the redundant AC/DC Power supply (fed from separate buses/mains to maintain operations while maintenance is being performed on one bus), Battery options and the UPS controller.
Having units like these on the market not only removes the abovementioned hurdle to reliable field power but when sized properly also gives you sufficient time to sort out your other problems or give you that time to bring your facility down in a safe manner.
Reliable field power also offers a number of opportunities to use remote I/O because now you can not only power the I/O unit itself but also ‘wet’ the loops as well. I am sure that there are many other potential opportunities that now present themselves to a knowledgeable End User – all it takes is your imagination or a conversation with your maintenance team about what they could do if they had power where and when it was required.
MERRY CHRISTMAS everyone, we will be back in early January with some prognostications for 2012. - Ian