Interlocks

The FastCCD needs pretty stringent interlocks, both on temperature and pressure. The tmperature interlocks are realized in hardware using a Lakeshore controller. Basically, if the temperature gets to high, we need to switch off the camera, if it gets too low, we switch off the chiller.

The pressure interlocks are switching off both the camera and the chiller, to avoid ice build-up. The relays switching the camera and chiller are intuitively called CHREL and CSREL, respectively.

Number	Device Parameter	Operator	Limit
c1	SCS_CDIDET_FCCD2M/GAUGE/PCC20.Value	GT	1e-3
c2	SCS_CDIDET_FCCD2M/TPUMP/TP1.state.RPM80	EQ	FALSE
c3	SCS_CDIDET_FCCD2M/TPUMP/TP2.state.RPM80	EQ	FALSE
c4	SCS_CDIDET_FCCD2M/VALVE/GV1.state.IsOpen	EQ	FALSE
c5	SCS_CDIDET_FCCD2M/VALVE/GV2.state.IsOpen	EQ	FALSE

Number	Logic	Action
a1	c1 or c2 or c3 or c4 or c5	COff

Vacuum

The vacuum system is shared with the TIM, which makes things a bit more complicated. If the FastCCD is vented, we better do not open the roughing valve unless TIM’s roughing valve is closed as well.

We use the turbo pump being running as an indicator that our vacuum is fine.

No	Property	Op	Value
c1	SCS_CDIDET_FCCD2M/GAUGE/P9.Value	GT	0.05
c2	SCS_BLD_TIM/VALVE/SRV3.state.IsClosed	EQ	FALSE
c3	SCS_CDIDET_FCCD2M/TPUMP/TP1.state.RPM80	EQ	FALSE
c4	SCS_CDIDET_FCCD2M/TPUMP/TP2.state.RPM80	EQ	FALSE

No	Logic	Action
a1	c1 or (c2 and c3 and c4)	CClose

No	Logic	Action
a1	c1 or (c2 and c3 and c4)	COff

Like always, if the turbo pumps fail, their gate valve should close. There is the same pumping down exception as for the DPS.

No	Property	Op	Value	Hyst	Timeout
c1	SCS_CDIDET_FCCD2M/TPUMP/TP1.state.RPM80	EQ	FALSE
c2	SCS_CDIDET_FCCD2M/GAUGE/PCC20.value	LT	1e-4	1	100000

No	Property	Op	Value	Hyst	Timeout
c1	SCS_CDIDET_FCCD2M/TPUMP/TP2.state.RPM80	EQ	FALSE
c2	SCS_CDIDET_FCCD2M/GAUGE/PCC20.value	LT	1e-4	1	100000

No	Logic	Action
a1	c1 and c2	CClose