Operator's Manual
Issue 14
/
Mar 2016 / UMC0071
Mercury
iPS
©2016 Oxford Instruments NanoScience. All rights reserved.
Page
56
The “Magnet Rate” MRFa example (Figure 16) shows how to split the range. In this example a
fast magnet rate limit of 10A/min is being applied for output currents from 0A to 70.0000A, then
fast magnet rate limit of 8A/min is being applied for output currents from 70.0001A to
120.5000A.
Figure 16. Rate limits table showing example magnet rate (MR) entries.
The “magnet rate” limits are applied when the switch heater is ON for systems configured with a
persistent switch, or all the time for systems configured without a persistent switch because for
systems without a switch, ramping the output will always be ramping the magnet.
The rates are applied as a coercive limit. If the operator sets a target ramp rate which is greater
than the limit being applied the magnet will ramp at the limit rate NOT the requested target rate.
The “Rate Limit” indicator on the Home screen will be asserted to inform the operator that the
requested ramp rate is not being delivered.
In the above MRFa example, if a magnet ramp rate of 9A/min were requested from 0A to 120A,
the ramp would proceed at 9A/min up to 70.0001A, then the limit would restrict the rest of the
ramp to 120A to 8A/min and the “Rate Limit” indicator on the Home screen is asserted for the
rest of the ramp.
