Relay Controlled Devices

Several devices, such as solenoid valves, are switched on and off (or open and closed) by toggling relays. In most instances, a 120 VAC latching relay is used, which in turn is controlled by the normally open contacts of two, momentary 5 V relays from a VME relay board (VMIc2232). For instance, one 5 V relay is used to energize the 120 V relay, and thus open a solenoid valve. A second 5 V relay deenergizes the 120 V relay, and closes the valve. Since the 5 V relays are momentary, the status of the solenoid does not change during an IOC crash or reboot. The position of the latching relay, and thus the valve, is read back into the computer using digital inputs located on the ADIO industry packs.

A list of the relay-controlled devices for the target, along with the digital readbacks, is tabulated below. Refer to the ADIO-IP and VMIc223 manuals for pin-out designations.

Device	Action	VMIc Relay	Digital Readback
Solenoid Valves
SV91108	Open	16	ADIO 1, ZB0
	Close	17	ADIO 1, ZB1
SV91110	Open	18	ADIO 1, ZC4
	Close	19	ADIO 1, ZB3
SV91111	Open	20	ADIO 1, ZB4
	Close	21	ADIO 1, ZB5
SV91115	Open	22	ADIO 1, ZB6
	Close	23	ADIO 1, ZB7
SV91115A$^1$	Open	23	ADIO 1, ZB6
	Close	22	ADIO 1, ZB7
SV91148	Open	24	ADIO 1, ZC0
	Close	25	ADIO 1, ZC1
SV91149$^2$	Open	25	ADIO 1, ZC2
	Close	24	ADIO 1, ZC3
OVC Controls
PV91104	Open	2	ADIO 2, ZB0
	Close	3	ADIO 2, ZB1
OVP91130	Start	4	ADIO 2, ZB2
	Stop	5	ADIO 2, ZB3
MP91132$^3$	Start	6	ADIO 2, ZB4
	Stop	7	ADIO 2, ZB5
Warm Return Valve
EV9177$^4$	Direction	0	na
	Enable	1	na

$^1$The magnet exhaust/recycle valves, SV91115 and SV91115A are controlled by a single 120 VAC relay. One valve is controlled by the Normally Open set of contacts, the other by the Normally Closed set. Therefore, only one pair of 5 V VME relays and one pair of digital inputs are necessary.

$^2$The refrigerator exhaust/recycle valves, SV91148 and SV911149 are controlled by a single 120 VAC relay. One valve is controlled by the Normally Open set of contacts, the other by the Normally Closed set. Therefore, only one pair of 5 V VME relays are necessary. Two pairs of digital inputs are used.

$^3$MP91132, the backing pump for the oil diffusion pump, is not connected to a relay, but is left running continuously. The software controls do exist for remote control however.

$^4$EV9177, the warm return valve, is controlled by two static (non-momentary) 5 V relays. The first sets a direction (energize = CLOSE). The second enables valve motion (energize = MOVE).