10
Pin connections at the auxiliary socket are:
Pin
Signal Name
Function
1
Output Bit 0
Stepper Motor
9
Output Bit 1
Stepper Motor
2
Output Bit 2
Stepper Motor
10
Output Bit 3
Stepper Motor
3
Output Bit 4
Fill Relay 1
11
Output Bit
5Fill Relay 2
4
Output Bit 6
Fill Relay 3
12
Output Bit 7
Alarm Relay 4
5
Input K4
Inhibit Autofill 1
13
Input K5
Inhibit Autofill 2
6
Input K6
Inhibit Autofill 3
14
Input K7
Initiate Autofill
7
+5 volt rail
15
Driver Protection / +11 volt rail
8
0 volt rail
3.5
Relay Contact
Connections Internal relays are available on ILM as an option. These have contacts rated
to carry up to 5 amps at up to 250 volts AC. They are intended for driving solenoid valves
or mains rated contactors directly. To ensure safety when using these relays, connections
to these relays are made via terminal blocks within the instrument. ILM should be
unplugged from its mains supply before removing the top cover to make connection to
the relay contacts. The incoming wires should be brought in via the cable gland on the
rear panel. After the connections have been made the cover should be replaced before
connecting ILM to the mains supply.
The connections are labelled TB1 to TB4 (corresponding to relays 1 to 4). Three terminals
are available for each relay. The terminal nearest the front of the instrument is the
Common contact. The middle terminal is the Normally Open contact and the terminal
nearest the rear panel is the Normally Closed contact. With the instrument switched off,
or the relay not active, Common is linked to Normally Closed. When the relay is active,
Common is linked to Normally Open.
3.6
Connections for Automatic Magnet Run Down
One common application of the relay contacts is to run down a magnet in the event that
the Helium level falls below the LOW threshold. Run down is initiated by providing a
contact closure to the magnet power supply. The contacts to be linked are pins 7 and 14
of the
PARALLEL I/O
socket on the IPS family of Oxford Instruments Power Supplies. (On
the earlier PS120-10 and PS120-3 power supplies, the same pin connections are used but
the socket is labelled
AUXILIARY I/O
on the rear panel.)
