When using the T9 system and running with too much rate in one FEE64 so the system is unbalanced.

I found a good way to understand this and to be able to operate the controls of the FEE64s was to place the Merger in "Pause" mode.

Then the data is extracted from the busy FEE64 but it can still be controlled.

When there is unbalance in the system it is possible for one or more queue in the Merger to become full and so the communication with that FEE64 is not possible.

Placing the Merger in Pause mode will mean all the data is discarded, the links run at full speed and action can be taken on the problem FEE64(s) to help balance the system out better.

I hope this helps .... it is highly likely that this is already being done.....

Perhaps a wise sequence when starting the whole DAQ is to operate with the Merger in Pause mode and  only switch it to merging when the user is happy with the rates.

In the statistics window of the FEE64 there is an indication of the data being transferred over the link.

When deciding how to run the experiment thought needs to be given to the various maximum rates. The rate from the FEE64 is 500k events/sec. If running with 26 FEE64 then this goes up to 13M events/sec. An event is 64 bits.

I'm not sure what the maximum rates are in the Merger and the TapeServer.