AMETEK PLA-PLW - Manual (Page 14)

Constant Power (CP):
The eLOAD will dissipate the power in accordance with the programmed value. It will automatically adjust the
current level inversely in response to a change in voltage.
Note: If the source voltage decays to zero volts the load will attempt to draw max rated current. If the OCP limit of the
eLOAD is greater than the current limit of the voltage source, the voltage source will be latched to the CC state. Otherwise
the OCP will trip to shutdown the load.
Programming Mode Parameters:
When programmed to a mode, the eLOAD remains in that mode until the mode is changed or until a fault
condition, such as an over power or over temperature occurrence. The current, voltage, resistance and power
mode parameters can be programmed without mode limitations. When a mode is selected via the front panel
or the digital interfaces, the associated parameters will then take effect at the instance of turning the input on.
Cross Mode:
According to the AMREL eLOAD design, the eLOAD has four operating modes: CC, CV, CR, and CP. As part
of our factory default settings, when switching from one mode to another mode in manual range (i.e. CV Low
to CC High), the final switched state will have the input turned off. If an application requires the input to stay
on when switching modes, the option “cross mode” must be changed from “input off” to “input remain.” By
changing the option, the load will switch between modes while keeping the input on, to accommodate for the
different applications of the DUT.
Note: Cross mode operation will work under both “manual” and “auto” range control mode.
Ranges:
Parameters may be programmed in any of the three overlapping ranges. The low range provides better
resolution at low settings. The range can be set using the front panel or via SCPI command. For auto-range
control: when you program a value, the eLOAD automatically selects the range that corresponds to the value
you program. If the value falls in a region where ranges overlap, the eLOAD selects one with the highest
resolution. In manual-range control: the programmed values will be limited by the current range setting, an
OUT OF RANGE message will appear on the front panel display when an invalid value is entered. When a
range is selected, the associated parameters (preset value or value from memory) will take into effect.
Cross Range Operation:
According to AMREL eLOAD design specification, the eLOAD has three overlapping operating ranges in each
mode. As part of our factory default settings, when switching from one range to another range in manual
mode (i.e. CV Low to CV High), the final switched state will have the input turned off. If an application requires
the input to stay on when switching ranges, the option “cross range” must be changed from “input off” to “input
remain.” By changing the option, the load will switch ranges while keeping the input on, to accommodate for
the different applications of the DUT. The cross range feature allows the user to effectively switch between
ranges based on the application needed by the DUT.
Note: Cross range operation will work under both “manual” and “auto” range control mode.
Immediate (Main) Level:
The immediate level can be set at front panel or via the digital interfaces. If the selected mode is active (Input
on), the new setting immediately changes the input at a rate determined by the soft-start turn-on sequence of
the unit. If the eLOAD is not in the selected mode, the new setting is saved until that mode is activated.
Transient Level:
The transient level can be set at front panel or via digital interfaces. The eLOAD input will switch between the
main level and the transient level when transient operation is turned on. During transient operation, the load
will switch from the immediate level to the transient level determined by the programmed slew time.
1-4