Martel Electronics 135 - Manual (Page 49)

DEC key to initiate the ramp from the ending value. If the trip detect is
enabled, you must press the INC or DEC key twice. See the trip detect
description on page 38 for more information. While the ramp is
slewing, the display will show:
The instantaneous value will be updating in the display. You will notice
periodic pauses in the display as the calibrator does internal calibration
cycles. This does not affect the output ramp and only causes a pause in
the displayed value.
The ramp function is accomplished by updating the output digital to
analog convertor (DAC) every 250 milliseconds with a new value. The
amount of output change for each update is a function of the total
ramp span and the length of time for the ramp to complete. The ramp
is capable of 1 LSD resolution per update. The actual resolution, or
amount of change per step, is dependent on the ramp amplitude and
time. The following formula can be used to calculate the ramp
resolution:
step size = (ending value – starting value)
(ramp time x 4)
Calculate the ramp time to achieve a desired resolution using this
formula.
ramp time = (ending value – starting value)
(step size x 4)
Auto Mode
This function continuously repeats the calibration points or output
ramp programs. If the ramp function is active when the AUTO key is
pressed the ramp function is cycled continuously. If trip detect was
enabled, it is canceled by the auto mode. If the ramp function is not
active, then the CalPts are cycled repeatedly. If CalPts were not
enabled, no action is taken.
Output Functions
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Slewing
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