2 out of 3 voting / How to find the unhealty transmitter and then indication the value
Please consider 3 transmitters in 2oo 3 vouting approch , first I would like to know how the unhealty transmitter in DCS can find , i.e. by camparsion the value of transmitters and consider the acceptable margin or other solution?Secondly how the value would be calculated after the unhealty transmitter / transmitters was/were found.
Since normally these configuration would be utilized in shut down or interlock system I m not sure which of following cases is true:
1- If one transmitter is unhealty and the other two transmitters are not showing the same value the interlock would be activated even none of transmitters rich the set points(interlock activated value HH or LL )
2-If one transmitter is unhealty and the other two transmitters are not showing the same value the interlock would not be activated until two of the transmitters rich the set point .
Thanks in advance