Lake Shore 625, User Manual

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Lake Shore Model 625 Superconducting MPS User’s Manual
5-10 Computer Interface Operation
Figure 5-4. Hardware Error Status Register
5.1.4.3.2 Operational Error Status Register Set
The Operational Error Status Register reports the following instrument operational error events: magnet discharging
through crowbar, magnet quench detected, remote inhibit detected, temperature high, high line voltage, external current
program error, calibration error. Any or all of these events may be reported in the standard event summary bit through
the enable register, see Figure 5-2. The Operational Error Status Register is the second value of the three values
associated with the Error Status Registers. The Error Status Enable command (ERSTE) programs the enable register and
the query command (ERSTE?) reads it. ERSTR? reads and clears the Error Status Register. The used bits of the Error
Status Event Register are described as follows:
Magnet Discharging Through Crowbar (MDC), Bit (6) – This bit is set to indicate that the magnet is currently
discharging through the crowbar. This can happen due to a hardware error or a power loss.
Magnet Quench Detected (QNCH), Bit (5) – This bit is set to indicate that a magnet quench has been detected.
Remote Inhibit Detected (OCF), Bit (4) – This bit is set if the remote inhibit condition has been detected.
Temperature High (OOV), Bit (3) – This bit is set if the internal temperature of the instrument exceeded 75 °C. The
current ramp will be stopped or the compliance voltage will be limited in an attempt to lower the internal temperature.
High Line Voltage (HLV), Bit (2) – This bit is set if the power line voltage exceeds an acceptable amplitude. Operation
can continue but additional heat may be dissipated by the instrument.
External Current Program Error (EPE), Bit (1) – This bit is set if the instrument cannot go into external or sum
current programming modes because the programming voltage is too high.
Calibration Error (CAL), Bit (0) – This bit is set if the instrument is not calibrated or the calibration data has been
corrupted.