Aim-TTI LD400, Инструкция по эксплуатации

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General Numeric Entry of Parameters
All user modifiable load parameters can be set using the numeric keypad. The desired parameter
is first selected from the menu using the soft-keys. The display then changes to show the
parameter entry screen which indicates the name of the parameter, its present value prior to
editing, and in most cases the entry limits and resolution. A message prompting for the entry of
the new value is shown. When any number key is pressed this prompt is removed and replaced
by the new value being constructed, and the soft-key labels change to show a list of units
applicable to the parameter being edited. The
CE
key deletes individual keystrokes; alternatively
the entire entry may be cancelled by pressing either the Home key or the Cancel soft-key.
Once the number entry is complete it must be terminated by pressing the required units soft-key
(choosing
A or mA , for example). The value is then checked against the parameter limits and, if it
falls within the allowed range, it is accepted and immediately implemented as the new value for
that parameter. If the value does not fall within the permitted range then an error message is
displayed and the buzzer will sound. If applicable the entry may be rounded to fit within the
specified parameter resolution.
Paragraphs below describe particular features associated with each parameter.
Variation of Parameter Values using
∆
Adjust
The level and transient parameters of the load can be adjusted by incrementing or decrementing
the present value using either the knob or soft-keys.
Note: this adjustment mechanism is only available whilst the instrument is on the home screen.
Two keys above the knob, labelled Levels and Transient , select the parameter to be modified
and initiate the adjustment. Pressing the Levels key initially selects Level A; a second press
selects Level B and a third press selects the Dropout Voltage setting. The cycle can be repeated
if required. Similarly, multiple presses of the
Transient key select between Frequency, Duty Cycle
and Slew Rate. A lamp above each of these keys blinks whilst adjustment is enabled and four
cursor soft-keys are shown.
The display of the selected parameter value is expanded to fill its edit box, with an adjustment
indicator ( ) positioned under the digit to be varied. The
◄ and ► soft-keys can be used to select
which digit position will be adjusted, and then either the knob or the
▲and ▼ soft-keys can be
used to increment or decrement the value at that position. Digits to the left of the one being
varied are automatically incremented or decremented when the decade overflow or underflow
point is reached. Digits to the right of the one being varied always remain unchanged unless a
point of decade resolution change is reached, in which case digits to the right may be lost
through truncation. If the least significant digit is being incremented and a decade resolution
change is reached, the new least significant digit becomes the one being adjusted.
Each change made is applied immediately, so long as the value remains within the permitted
limits of that parameter. If an increment or decrement of the current position would exceed a
range limit then the parameter value remains unchanged; partial adjustments are not made.
Pressing the Off soft-key or the Off key above the knob (or the
Home
key) ends the adjustment,
retaining the new value, and returns the display to the home screen. Pressing the Cancel soft-
key ends the adjustment and restores the last parameter to the value it had when it was selected
for adjustment.
Configuring the Load
The normal sequence of operation is to select the load Mode, set the required operating Level
and Dropout Voltage, and then Enable the input. If transient operation is required, the second
Level setting and the Slew Rate parameters must be set, as well as the frequency and duty cycle
of the internal oscillator if it is to be used.
The home screen shows all the parameter settings, which can be viewed before the input is
enabled. All parameters except load Mode and level Range can be adjusted as required while the