Arc supervision signal - Lincoln welder

Hi all,

Does anyone know which signal I could use to monitor at any time if the arc is well established ?
I have an IRC5

It looks like siLn1Arc_Est does the job. Yet, it is not available in the signal list to be used for a cross connection. Anyone knows how to use this input ? (e.g. transmit it to a plc )

Although it is not possible to make a cross connection in the configuration topic from robotstudio itself, adding it manually directly into the EIO file solves the problem