Dynamic Generation:Tristate Mode Property

NI Digital Waveform Generator/Analyzer Help

Edition Date: June 2013

Part Number: 370520P-01

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Short Name: TristateMode

Property of niHSDIO

Specifies the action taken by NI-HSDIO when a channel is tristated. A tristate condition can occur during initial states , idle states , per cycle tristate , and static tristate. Selecting High impedance sets the channel to a high-impedance state when tristated. To drive a termination voltage on a channel in a generation session, select Drive termination voltage .

You must set this property to the same value on a channel in both acquisition and generation sessions, or NI-HSDIO returns an error. If you are using both acquisition and generation sessions in your application, when you select a value for this property in a session, NI-HSDIO automatically sets the same value in the other session. However, NI-HSDIO allows you to change the value only in the original session in which you configured it. For example, if you select High impedance in your acquisition session, your generation session is configured automatically to the same value. If you want to change the value to Drive termination voltage, you can do so only in the acquisition session until you close the original session.

Note   If you set the Termination Mode and Tristate Mode properties to different values on the same channel, NI-HSDIO returns an error.

You can select the following PFI channels and clocks for the active channel input of the property node using these strings: PFI1 , PFI2 , STROBE , and DDC_CLKOUT . These strings are not case sensitive and can be grouped with the standard input strings separated by commas. The following are examples of valid string syntax: 0, 4, 6, PFI1, 7 or 0-12, STROBE, DDC_CLKOUT.

This property is valid only for generation sessions.

Note  This property is supported only on NI 6555/6556 devices.
High impedance (84)

Digital driver is disabled when tristated. This value is the default.

Drive termination voltage (85)

The channel drives the specified termination voltage when tristated.


The following table lists the characteristics of this property.

Datatype iL
High-level VIs N/A
Channel-based Yes


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