Lake Shore 625, User Manual

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Lake Shore Model 625 Superconducting MPS User’s Manual
Installation 3-5
3.5.2 Remote Voltage Sense
The Model 625 provides a connection for remote voltage sense leads. This connection is normally used to measure the
voltage at the magnet allowing a more accurate reading of magnet voltage by eliminating voltage drops in the leads
connecting the power supply to the magnet. This voltage reading can be displayed on the front panel or read over the
computer interface. Refer to Paragraph 4.4.2 to configure the display to show the remote voltage sense reading. The
remote voltage sense connection is a differential input capable of reading ±5 V and an input impedance of > 50 k

.
3.5.3 Output Current and Voltage Monitors
The output current and output voltage of the power supply can be monitored externally using the monitor output
connections on the Analog I/O connector. Each output is a buffered, differential, analog voltage representation of the
signal being monitored. The current monitor has a sensitivity of 1 V = 10 A and the voltage monitor has a sensitivity of
1 V = 1V. Both outputs have a source impedance of 20 Ω.
3.6 DIGITAL INPUT/OUTPUT CONNECTIONS
The Digital I/O connector provides connections to digital control signals. Two of these connections, Remote Inhibit and
Trigger In, are inputs used to control the state of the power supply. The Fault Out is an output that is used to signal error
conditions.
Digital_IO.bmp
Pin Name Pin Name
1
2
3
4
5
6
7
8
9
10
11
12
13
Fault Out Common
NC
Remote Inhibit Common
NC
Trigger Out Common (not used)
NC
Trigger In Common
NC
NC
NC
NC
NC
NC
14
15
16
17
18
19
20
21
22
23
24
25 Fault Out
NC
Remote Inhibit
NC
Trigger Out (not used)
NC
Trigger In
NC
NC
NC
NC
NC
Figure 3-4. Model 625 Digital Input/Output Connector
3.6.1 Fault Output
The fault output is a relay contact closure that closes to indicate a fault condition. The relay contact is rated at 30 VDC at
1 A. The contact closure alerts other system components of the fault. If the power supply detects an internal hardware
fault, the fault relay is closed, the front panel fault LED is lit, and the condition is latched. If the power supply detects an
operational fault, the fault relay will close for 1 second and then open and the front panel LED will blink. When two
Model 625s are connected in parallel, the fault output should be wired to the remote inhibit line of the other supply.
Refer to Paragraph 3.9 for details on connecting two power supplies in parallel.