BaBar Injection State Machine

For the implementers of subsystems

Outline

BaBar has three states (shown to PEP):

1. INJPMT
2. INJDENY
3. SAFEINJ

PEP has the following flags:

• INJREQ
• Injecting

The protocol is:

BaBar changes from INJDENY to INJPMT
PEP sets INJREQ
BaBar's subsystems tell CEN-BIP, safe to inject
BaBar changes from INJPMT to SAFEINJ
PEP sets Injecting

PEP removes Injecting and INJREQ
BaBar changes from SAFEINJ to INJPMT

What to implement

Systems should look at the mirrored PEP-II INJREQ flag (CEN:BIP:PEP:INJREQ). This is a bi record where 1 is the INJREQ. Contact Perry or Kenneth to have your system's safe flag added to the state machine. The crash button, which causes the BaBar state to go to INJDENY is CEN:BIP:BBR:ABORT. Set it to 1 momentarily to cause an abort.

Note, there is a timeout in which your system should respond to the INJREQ. This will be adjusted as the state machine becomes better connected to the other systems.

Future plans

The state machine will attempt to better regulate the injection rate and also be able to mediate some of the High Voltage actions.