last update 050131

Timing in the STAR Trigger

The timing for the STAR trigger is shown in the - Timing diagram. All of the timing for the trigger is controlled by the delay between the leading edge of the heartbeat (TS) and the occurence of the interaction. This is set by programmable delays on the RHIC workstation for the Yellow ring V124 unit, channel 7. Once we get this correct, the rest of the timing internal to the trigger is ready, except for the BRB and YRB signals, which must be timed separately. The timing for these signals is also set on the V124 control pages, channel 2 in each unit.

Pretrigger

We also provide a pretrigger signal which is available well in advance of the Level 0 accept signal. The pretrigger is formed using the BBC discriminator outputs.