BS7273-4 Costs £168 (member = £84)
That was published in 2007, so to date that has cost you £6.22 a month.
How many jobs have you done since April 2007? Im sure by putting a few pence extra on each job (inflation!) you can cover the costs of the new guides.
You make some valid point Piglet but the actual cost to my business could run into thousands and thousands simply because there are those few amongst us who try and follow all the rules to the best of our ability, and there is everybody else be they jack of all electricians or large national fire companies that ignore the likes of 7273-4.
I think its generally accepted (ish) that presently there may be one addressable loop powered I/O unit that will meet the failsafe criteria for a Cat A door.
The only other way this can be achieved to comply with 7273-4 that I can see is by running separate cables back to the control panel.
This is additional cost, this loses me jobs. Does the customer care ... No.
Yes he should care, yes he may end up in prison, but he probably doesn't even know the Standard exists or the risks because my 15 page quote and specification doesn't make it passed the electrical contractor I'm quoting to because he gets a cheaper quote from dodgy git inc.