© National Instruments | 6-5M Series User ManualUsing an Internal SourceTo use DO Sample Clock with an internal source, specify the signal source and the polarity ofthe signal. The source can be any of the following signals:• AI Sample Clock (ai/SampleClock)• AI Convert Clock (ai/ConvertClock)• AO Sample Clock (ao/SampleClock)• Counter n Internal Output• Frequency Output• DI Change Detection OutputSeveral other internal signals can be routed to DO Sample Clock through RTSI. Refer to DeviceRouting in MAX in the NI-DAQmx Help or the LabVIEW Help for more information.Using an External SourceYou can route any of the following signals as DO Sample Clock:• PFI <0..15>• RTSI <0..7>• PXI_STAR• Analog Comparison Event (an analog trigger)You can generate samples on the rising or falling edge of DO Sample Clock.You must ensure that the time between two active edges of DO Sample Clock is not too short. Ifthe time is too short, the DO waveform generation FIFO is not able to read the next sample fastenough. The DAQ device reports an overrun error to the host software.Routing DO Sample Clock to an Output TerminalYou can route DO Sample Clock out to any PFI terminal. The PFI circuitry inverts the polarityof DO Sample Clock before driving the PFI terminal.I/O ProtectionEach DIO and PFI signal is protected against overvoltage, undervoltage, and overcurrentconditions as well as ESD events. However, you should avoid these fault conditions byfollowing these guidelines:• If you configure a PFI or DIO line as an output, do not connect it to any external signalsource, ground, or power supply.• If you configure a PFI or DIO line as an output, understand the current requirements of theload connected to these signals. Do not exceed the specified current output limits of theDAQ device. NI has several signal conditioning solutions for digital applications requiringhigh current drive.Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
