hi,
im trying to build industrial analog front end that can be configured by software to accept (4-20mA) or (0-10V / 1-5V / etc) on same connector pin
where accuracy doesnt matter that much
output to be connected with a filtering cap 10nF or so..
for switching i dont like to use relays due to relaiblity issues so
im thinking about SSR like AQY282S (with TVS with Voltage @Ipp < 60v)
also becasue there is 2 ssr per configuration it means 2x resistance =~5 ohm (ie 5% of 4-20mA lost?)
but this would require 4 ssr for 1 channel .. they arent cheap (1.5$ each).
also it will require a not gate for 2/4 ssr.. overall i think there should be simpler way i didnt think about?
so what would be the alternative robust configurable analog front end?
I'm wondering what way being used in PLCs.
and if the above way is good enough or not ?