While viewing the logic forcing display in an HMI of Mark V (DOS based), it is usual to see the forced values (either 0 or 1) in the C processor along with R, S and T? What can be the probable cause if the value is being displayed only for C, and not for R, S or T? Can it be a communication failure? If so, what can be the further consequences of the same, and what is the remedy?

Plz help.

 

Is this only for some values in Logic Forcing or for them all? If it is only some points that only show <C>, then it is logic which is non-critical, non-voted and only exists in <C>. Can you give some examples?

 

Actually, it was for all the logics that had been kept forced. Also, machine was not accepting commands from the <I> station although all data could be monitored. The problem was solved upon pressing the reset button on C processor. This is the third time this has happened. Can you please clarify as to what might be the root cause behind this?

 

Dear Calvein,

It might be data frozen issue. it will be solved once <C> rebooted. I am not sure for the reason. We too had this issue but after upgrade <I> from DOS to HMI we never notice this kind of issue now.

Good luck
Take care
G.Rajesh

 

It may as simple as a connection on the DENET between <C> and RST or it may be a problem in <C>.

Next time you have a chance, check the DENET connection on the LCCB board on <C>. If you have a spare LCCB board, change it out.