Ametek Amrel PLA 2U, Operation Manual

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M470039-01 REV-F Page 15
Constant Resistance (CR):
The electronic loa d will sink a current linea rly proportiona l to the input volta ge in a ccorda nce with the progra mmed
va lue.
Constant Power (CP):
The electronic loa d will dissipa te the power in a ccorda nce with the progra mmed va lue. It will a utoma tica lly a djust the
current level inversely in response to a cha nge in volta ge.
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 progra mmed to a mode, the electronic loa d rema ins in tha t mode until the mode is cha nged or until a fa ult
condition such a s a n overpower or over tempera ture occurrence. The current, volta ge, resista nce a nd power mode
pa ra meters ca n be progra mmed whether or not the mode is presently a ctiva ted. When a mode is selecte d via the front
pa nel or via the digita l interfa ces, the a ssocia ted pa ra meters will then ta ke effect a t the insta nce of turning the input on.
Cross Mode:
According to AMREL eLoa d design, the electronic loa d ha s four opera ting modes. As pa rt of our fa c tory defa ult settings,
when switching from one mode to a nother mode in ma nua l ra nge (i.e. CV Low to CC High), the fina l switched sta te 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 a ccommodate for the different a pplica tions of the DUT.
Note: Cross mode operation will work under both “manual” and “auto” range control mode.
Ranges:
Pa ra meters ma y be progra mmed in a ny of the three overla pping ra nges. The low ra nge provides better resolution a t low
settings. The ra nge ca n be set using the front pa nel or via SCPI comma nd. For a uto-ra nge control: when you progra m a
va lue, the electronic loa d a utoma tica lly selects the ra nge tha t corresponds to the va lue you progra m. If the va lue fa lls in a
region where ra nges overla p, the electronic loa d selects one with the highest resolution. In ma nual-ra nge control: the
progra mmed va lues will be limited by the current ra nge setting, a n OUT OF RANGE messa ge will a ppea r on the front
pa nel displa y when a n inva lid va lue is entered. When a ra nge is selected, th e a ssocia ted pa ra meters (preset va lue or va lue
from memory) will ta ke into effect.
Cross Range Operation:
According to AMREL eLoa d design specifica tion, the electronic loa d ha s three overla pping opera ting ra nges in ea ch
mode. As pa rt of our fa ctory defa ult settings, when switching from one ra nge to a nother ra nge in ma nua l mode (i.e. CV
Low to CV High), the fina l switched sta te will ha ve the input turned off. If a n a pplica tion requires the input to sta y on
when switching ranges, the option “cross range” must be changed from “input off” to “input remain.” By changing the
option, the loa d will switch ra nges while keeping the input on, to a ccommodate for the different a pplica tions of the DUT.
The cross ra nge fea ture a llows the user to effectively switch between ra nges ba sed on the a pplica tion needed by the DUT.
Note: Cross range operation will work under both “manual” and “auto” ra nge control mode.
Immediate Level:
The immedia te level ca n be set a t front pa nel or via the digita l interfa ces. If the selected mode is a ctive (Input on), the
new setting immedia tely cha nges the input a t a ra te determined by the soft -sta rt turn-on sequence of the unit. If the
electronic loa d is not in the selected mode, the new setting is sa ved until tha t pa rticula r mode is a ctiva ted.