Programming Mode Parameters - Ametek Amrel PLA Series Operation Manual

Constant Resistance (CR):
The electronic load will sink a current linearly proportional to the input voltage in accordance with the programmed
value.
Constant Power (CP):
The electronic load 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
electronic load 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 shut down the load.

Programming Mode Parameters:

When programmed to a mode, the electronic load remains in that mode until the mode is changed or until a fault
condition such as an overpower or over temperature occurrence. The current, voltage, resistance and power mode
parameters can be programmed whether or not the mode is presently activated. When a mode is selecte d via the front
panel or via the digital interfaces, the associated parameters will then take effect at the instance of turning the input on.
Cross Mode:
According to AMREL eLoad design, the electronic load has four operating modes. 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 electronic load automatically selects the range that corresponds to the value you program. If the value falls in a
region where ranges overlap, the electronic load 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, th e associated parameters (preset value or value
from memory) will take into effect.
Cross Range Operation:
According to AMREL eLoad design specification, the electronic load 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" ra nge control mode.
Immediate 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
electronic load is not in the selected mode, the new setting is saved until that particular mode is activated.
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