User manual

PicoScope 6000 Series Programmer's Guide 67

3.9.40

ps6000SetExternalClock

PICO_STATUS ps6000SetExternalClock

(

short handle,

PS6000_EXTERNAL_FREQUENCY frequency,

short threshold

)

This function tells the scope whether or not to use an external clock signal fed into the

AUX input. The external clock can be used to synchronise one or more PicoScope 6000

units to an external source.

When the external clock input is enabled, the oscilloscope relies on the clock signal for

all of its timing. The driver checks that the clock is running before starting a capture,

but if the clock signal stops after the initial check, the oscilloscope will not respond to

any further commands until it is powered down and back up again.

Note: if the AUX input is set as an external clock input then it cannot also be used as

an external trigger input.

Applicability

All modes

Arguments

handle, the handle of the required device

frequency, the external clock frequency. The possible values are:

PS6000_FREQUENCY_OFF: the scope generates its own clock

PS6000_FREQUENCY_5MHZ: 5 MHz external clock

PS6000_FREQUENCY_10MHZ: 10 MHz external clock

PS6000_FREQUENCY_20MHZ: 20 MHz external clock

PS6000_FREQUENCY_25MHZ: 25 MHz external clock

The external clock signal must be within ±5% of the selected

frequency, otherwise this function will report an error.

threshold, the logic threshold voltage:

-32,512

-1 volt

0 volts

32,512

+1 volt

Returns

PICO_OK

PICO_USER_CALLBACK

PICO_INVALID_HANDLE

PICO_INVALID_PARAMETER

PICO_DRIVER_FUNCTION

PICO_EXTERNAL_FREQUENCY_INVALID

PICO_FW_FAIL

PICO_NOT_RESPONDING

PICO_CLOCK_CHANGE_ERROR