5-6
IM DL850E-01EN
Pulses per Rotation (Pulse/Rotate)
When the time base is an external clock, you can specify how many pulses of the external clock signal (how
many sampled data acquisitions) correspond to one mechanical rotation (or period). For example, if you set
Pulse/Rotate to 100 pulses, when the record length is 1 kpoint, 10 rotations worth of sampled data will be
acquired. When Pulse/Rotate is set to 1 pulse, each point of sampled data corresponds to a single rotation.
The Pulse/Rotate setting only affects the horizontal-cursor measurement values and how the time axis is
displayed on the screen. For example, if you set Pulse/Rotate to 100 pulses, when the record length is 1 kpoint,
1 div will correspond to 1 rotation. With these settings, if you move the cursor by 1 div, the measured horizontal
value will increase or decrease by 1.
Selectable range for pulses: 1 to 24000
Notes about Sampling Using an External Clock Signal
• You cannot acquire waveforms when the acquisition mode is set to Envelope or BoxAverage.
• You cannot display waveforms in roll mode.
• There is no function for dividing the frequency of the clock signal.
• The time axis cannot be changed. To change the time-axis display range, change the record length, or
zoom in on the time axis.
• The measured time values in cursor measurements and automated measurements of waveform
parameters indicate the number of clock signal pulses. For these measurements, units are not displayed.
• Hard disk recording cannot be used.
• The dual capture feature cannot be used.
• The trigger settings listed below are invalid.
Hold-off, trigger delay, period trigger, pulse width trigger
Maximum Sample Rates for Each Module
If you set the sample rate of the DL850E/DL850EV to a rate that is higher than a module’s maximum sample
rate, because the data is updated at the module’s maximum sample rate, all the data within the module’s data
update interval will be the same. The maximum sample rates for each module are listed below.
Module
Maximum Sample Rate
Internal Clock
External Clock
701250/701255
10 MHz
9.5 MHz
701251
1 MHz
1 MHz
701267/701270/701271/701275
100 kHz
100 kHz
701261/701262
(when measuring voltage)
100 kHz
100 kHz
(when measuring temperature)
500 Hz
500 Hz
701280
25 kHz
25 kHz
701265
500 Hz
500 Hz
720210
100 MHz
9.5 MHz
720220
200 kHz
200 kHz
720221
100 kHz
100 kHz
720230
10 MHz
9.5 MHz
720240/720241
100 kHz
100 kHz
Notes about Using the 16-CH Voltage Input Module (720220)
Notes about Using the 16-CH Temperature/Voltage Input Module (720221)
5 Waveform Acquisition