User guide

Table Of Contents
Rev. 5 77
Operation
Ramping Functions : Ramping to Zero
Programmer out of PAUSED mode. The ramp rate will be controlled by the
preset ramp rate variables as described in section 3.7.1 on page 33.
3.12.4 Ramping to Zero
Pressing the RAMP TO ZERO key activates an immediate ramp to zero
field/current. See section 3.6.4 on page 31 for details.
3.12.5 Fine Adjust of Field / Current in Holding Mode
If the target field/current menu is active and the Model 430 Programmer is
in HOLDING mode (indicated by a “–” Status Indicator), the fine adjust
knob can be used to manipulate the output current. While at the target
field/current menu, press
SHIFT, followed by FINE ADJUST. This will
allow fine adjustment of the field/current (see section 3.4).
When the fine adjust knob is turned the Model 430 Programmer will follow
the target current as it is adjusted, at the defined ramp rate for the
segment in which it is operating. Adjustment of the current is prevented
from exceeding the Current Limit specified in the Load setup menu (see
section 3.10.2.4 on page 52). The resolution of the adjustment is 15 digits,
which is greater than the resolution of the display.
When the field/current is adjusted to the desired value, press the
ENTER
key to keep that value as the target field/current. If any other operation is
performed before
ENTER is pressed, the target field/current value will
revert back to what it was before adjustment using the fine adjust knob
was initiated, and the current will immediately begin ramping back to that
value.
3.13 Persistent Switch Control
The Model 430 Programmer includes an integral persistent switch heater
that provides the capability of controlling the persistent mode of the
magnet either locally from the front panel of the Model 430 Programmer
using the
PERSIST. SWITCH CONTROL key
1
, or remotely through a
communications interface. The persistent mode of the magnet is indicated
by the
MAGNET IN PERSISTENT MODE LED
2
.
1. Refer to section 3.6.1 on page 29.
2. Refer to section 3.8.2.2 on page 40.
+20.02 A - Target Current (A)
+0.20 Vs +20.0239