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Scan Engine Process

NI InsightCM™ SDK Help

Edition Date: July 2017

Part Number: 375191C-01

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This process acquires data from channels on modules whose sampling mode property is single-point. These channels acquire a single value per read instead of continuously acquiring samples at a high sampling rate. In other words, this process does not acquire data as waveforms. This process relies on the NI Scan Engine interface rather than the FPGA interface, which means it reads and updates all single-point values at a one-second sample rate.

Actions Performed

Reads one single-point value per second from channels on static C Series modules.

Communicating with this Process

The SDK does not provide any messages you can send to this process specifically. This process periodically acquires a sample from all physical channels on static modules.

Role within the Dataflow Script

This process does not start or advance the Dataflow Script. However, the values of single-point channels pass through Dataflow Script through the following process:

  1. For each single-point channel, the Scan Engine process adds a map point to a point value map whose name is the same as the data group to which the channel belongs.
  2. One of the following processes duplicates these maps and bundles them in the requests it makes to start the Dataflow Script:
    • For data groups that contain only single-point channels, the Single Point Clock process sends a message to start a Dataflow Script iteration once per second.
    • For data groups that also contain waveform channels, the FPGA Acquisition process starts the Dataflow Script when it finishes a read operation.

For an illustration of this behavior, refer to Relationship between Data Acquisition Processes and Dataflow Script.

Inputs

If the configuration for a channel contains slope and intercept properties for scaling its values, this process reads and applies them.

Outputs

Writes one map point per single-point channel. The value of each point is the latest channel value after any scaling.

Related Information

Single-Point Clock Process


 

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