BaBar Injection

This document seeks to explain the sequences, handshaking, and displays written thus far on the BaBar side of the PEP-II injection protocols.

The Tripped States will never be entered into because nothing can cause the sequences to set the Tripped state!

Screens

pepstat.dl

This is the uppermost level BaBar - PEP Display. It summarizes the PEP rings in the ACC HER and ACC LER Buttons. The PEP Injection Values are shown in the BIC LER and BIC HER Displays.

Several fields have been removed temporarily. The IP Parameters and the Beam Energies have been removed until they are defined and exported from PEP and MCC.

bipinj.dl

The Beam Abort Button puts BaBar into INJDENY state where PEP-II cannot inject.

The Test Controls Button is a temporary control panel to stimulate and debug the Injection State Machines

The Timeout Countdown indicator tells how many seconds remain for the systems to go to safe before the state machine raises an alarm. The alarm does not prevent injection.

bipinj_ctl.dl

You will have to be the PEP-II State machine, all the subsystems, and BaBar operator. All these controls are, as of the writing of this document, not connected to anything other than these screens. The state machine is also disconnected except for the screen indicators.

The Manual HV Preparation button allows the Operator to suggest that the HV systems prepare for data taking by energizing high voltage or to prepare for injection by dropping to lower voltages. The injection machine will override the manual control when it is necessary.

• BaBar Operator: INJDENY (equivalent to Beam Abort), INJPMT, Manual HV Preparation, SVT Bypass, and DCH Bypass.
• PEP-II State Machine: INJREQ, Injecting
• Subsystems: SVT Safe, DCH Safe

Indicators

• BaBar Status: (soft mbbi CEN:BIP:BBR:STR)
  • Armed - One of the safeties is not engaged.
  • Safe - BaBar is safe for injection.
  • Tripped
• PEP State: (soft bi CEN:BIP:PEP:INJREQ and soft bi CEN:BIP:PEP:INJECTING)
  • NoInjReq - PEP-II is not requesting injection.
  • InjReq - PEP-II is requesting injection.
  • NotInjecting - PEP-II is not injecting.
  • Injecting - PEP-II is injecting.
• PEP Status:
  • Idle
  • Waiting - PEP-II is waiting for BaBar.
  • Ready - PEP-II has BaBar approval and is ready to inject.
  • Injecting
  • Tripped
  • Stored - PEP-II had just been in the Injecting state and has not changed state.
• BaBar State:
  • INJDENY - PEP-II is not allowed to inject.
  • INJPMT - PEP-II can request injection.
  • SAFEINJ - PEP-II may inject.
• PEP-II ACC:
  • Connected - At least one of the channels is connected.
  • Not Connected - None of the channels are connected.
• PEP-II BIC:
  • Connected - At least one of the channels is connected.
  • Not Connected - None of the channels are connected.
• HV
  • Down - HV is at a low voltage.
  • Up - HV is at high voltage.

Sequences

In general these sequences all derive their outputs from the states controlled by inj.st. In principle, they could be integrated completely into one state machine, but doing so would increase chances for programmer error.

enhance.st

This sequences enhances the state descriptions of PEP and BaBar. It drives the BaBar Status and PEP Status displays. The only inputs are the BaBar State, HV, PEP INJREQ, and Injecting.

In order to capture all possible flag combinations, the states are combined into one integer via a macro and the output status descriptions were assigned by hand.

hv.st

This allows manual control over the HV to an extent. The sequence locks out manual control once PEP-II asserts INJREQ or if BaBar asserts SAFEINJ.

inj.st

This is the big sequence. If this goes, most of the others go.

What is supposed to happen is:

• BBR: INJDENY to INJPMT
• PEP: put INJREQ
• BBR: [waits for systems to say safe]
• BBR: INJPMT to SAFEINJ
• PEP: put Injecting
• PEP: get INJREQ and Injecting
• BBR: SAFEINJ to INJPMT

If possible, remove the PEP:INJREQ before Injecting. This will prevent the sequence from looping back around, which is not harmful. Also adding a delay to the done state in the inj.st sequence file would do the trick.

Aborts

I think there should be three abort levels: Fatal, Abort, and Reduce. Reduce would reduce the injection rate. Abort would terminate current injection but still allow the next one. Fatal would stop injections and prevent all further ones.

When a channel connection is lost, the abort goes to INJPMT. Any assertion of INJDENY will cause immediate abort. Please use the Beam Abort Channel if possible. If some protocol violation occurs,

pepcxn.st

This sequence monitors connections to BIC IOC. When all the channels are lost, the PEP-II BIC is changed to Not Connected.

summary.st

This sequence summarizes and monitors connections to the ACC data. When all the channels are disconnected, PEP-II ACC is changed to Not Connected. The summaries map colors from the SCP color rules to the BaBar standard colors. Peach and light blue are mapped to white. Yellow is mapped to yellow and green is mapped to green. All others are mapped to red (I think).

expect.st

Controls expected lights for CEN-MON only. This is a modified copy of CEN-MON's expected sequence. These sequences drive the lights on the BaBarStatusDAQ and BaBarStatusDetector Displays. They pass the severity through except when we expect them and they go invalid. In that special case, the severity turns major.

The expected flags are all stored on CEN-MON. The expected flags also disable the error summary fields that drive the vmeerr and iocerr displays.