The gas pressure supervision subfunction monitors the gas pressure inside the arc chamber.
The operation of the subfunction can be described with a module diagram. All the modules in the diagram are explained in the next sections.
The gas pressure is monitored through the binary input signals PRES_LO_IN and PRES_ALM_IN.
Timer 1
When the PRES_ALM_IN binary input is activated, the PRES_ALM alarm is activated after a time delay set with the Pressure alarm time setting. The PRES_ALM alarm can be blocked by activating the BLOCK input.
Timer 2
If the pressure drops further to a very low level, the PRES_LO_IN binary input becomes high, activating the lockout alarm PRES_LO after a time delay set with the Pres lockout time setting. The PRES_LO alarm can be blocked by activating the BLOCK input.