Hi,
thanks for the reply

In Programmable Logic I had to reverse the ph alarm, because otherwise I never dosed.
but I don't understand the ph alarm. I set the ph nominal value 8.2 hysteresis 0.1. but the alarm puts me maximum deviation 0.5 then the alarm jumps when the ph is greater than 8.7 and I want it to jump when the ph is greater than 8.3

best regards
Pelayo