On 30/08/2020 10:49, T i m wrote:

Adrian was concerned about safety and we all know that the simpler a
solution the lower the chance of failure (MTBF).


The way one normally deals with safety critical software systems, is by
working very hard to avoid any of the software being safety critical in
the first place. Typically this is done with hardware interlocks, since
they can usually be rigorously "proven" much more easily.

So for example with a kiln, you could have a max temperature sensors
that is hardwired into your safety relay/contactor, so should the temp
ever not be indicated as safe by all the sensors it trips out power to
the heaters. (software can obviously finesse that and log and report the
event etc)



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/