ADLINK USB-2405 - Manual (Page 50)

40 Operation
Calculation of the pulse frequency and duty cycle is as follows.
3.4.4 Digital Trigger IN for Continuous Analog Input
The GPIO can be programmed as the digital trigger source for
continuous analog input acquisition. Please see External Digital
Triggering for details.
3.4.5 Synchronization Sample Clock IN
To synch multiple devices, the GPIO can be programmed as exter-
nal sample clock input, with the same trigger signal and external
sample clock applicable to multiple USB-2405s to achieve more
than 4 channel synchronization without phase delay. Note the syn-
chronization sample clock must be continuous, with valid fre-
quency range from 1 kHz to 128 kHz.
cnt length Pulse cnt initial Pulse
cnt length Pulse
Duty
cnt length Pulse cnt initial Pulse
F
F
PWM
Timebase
PWM
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