NI 9467 (FPGA Interface)

NI CompactRIO Device Drivers Help

Edition Date: December 2017

Part Number: 373197L-01

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CompactRIO GPS Timing and Synchronization Module

FPGA I/O Node

This device does not support any FPGA I/O Nodes.

Module Methods

Use the FPGA I/O Method Node to access the following I/O methods for this device.

Method Description
Wait for PPS Waits until a new PPS is detected, indicating the start of a new second.
Note Note  The NI 9467 Module does not generate a PPS at start-up. The module begins generating a PPS only after it obtains the first location fix. This takes 30 seconds or more of access to GPS satellite signals with a clear view of the sky.
This method has the following parameters:
  • Timeout (Ticks)—Specifies in FPGA clock ticks how long the Wait for PPS method waits for the PPS to occur. A value of 0 causes the Wait for PPS method to time out immediately, a negative value causes the Wait for PPS method to wait indefinitely, and a positive value causes the Wait for PPS method to wait for that number of clock ticks before timing out.
  • Timed Out—Returns a Boolean value. A value of TRUE indicates that a timeout occurred.
Note Note  The timeout counter starts counting only when module startup is complete.
Wait for Data Update Waits until new data is received for the last PPS and the properties are updated. At start-up, when the PPS generation has not started, this method indicates the periodic update of the GPS Status, Antenna Status, and Number of Satellites properties.
Note Note  In the time between the PPS and when this method completes, the properties update at different times. Therefore, do not read properties during this time. Instead, read them after the Wait for Data Update method completes.

This method has the following parameters:
  • Timeout (Ticks)—Specifies in FPGA clock ticks how long the Wait for Data Update method waits for the update to occur. A value of 0 causes the Wait for Data Update method to time out immediately, a negative value causes the Wait for Data Update method to wait indefinitely, and a positive value causes the Wait for Data Update method to wait for that number of clock ticks before timing out.
  • Timed Out—Returns a Boolean value. A value of TRUE indicates that a timeout occurred.
Note Note  The timeout counter starts counting only when module startup is complete.
Reset ModuleThis method makes the module reinitialize to its start-up state.
Note Note  When the module is reset, it stops generating a PPS. The module starts generating a PPS again after it obtains the first location fix. This takes 30 seconds or more of access to GPS satellite signals with a clear view of the sky.

Module Properties

Use the FPGA I/O Property Node to access the following module properties for this device.

Note Note  In the time between the PPS and when the Wait for Data Update method completes, the properties update at different times. Therefore, do not read properties during this time. Instead, read them after the Wait for Data Update method completes.
Property Type Description
PPS Timestamp (TAI) Read Returns a U64 value representing the TAI timestamp in nanoseconds of the last PPS.
UTC Offset Read Returns an I8 value representing the current offset between TAI time and UTC time in seconds. To compute UTC time, the UTC Offset must be subtracted from the TAI time (UTC_Time = TAI_Time – UTC_Offset).
Note Note  The GPS satellites transmit the UTC Offset information only once every 12.5 minutes. This property reports invalid values for up to 12.5 minutes after start-up. Use the UTC Offset Valid property to determine when this property starts returning valid values.
UTC Offset Valid Read Returns a Boolean indicating if the UTC Offset and leap second information has been received from the GPS satellites, making the UTC Offset, Leap Second Pending, Leap Second Direction, and Leap Second Occurred properties valid.
GPS Status Read Reports the current GPS status:
  • Normal—The module is operating properly.
  • Unable to get fix—The module is unable to compute a location fix and generate a precise PPS. This occurs during start-up and when the satellite signals are obstructed.
  • Initializing—This status is reported at start-up or after a module reset until the module is initialized.
Self-Survey Complete Read Returns True if the self-survey is complete and False if the self-survey is still in progress.
Antenna Status Read Reports the current antenna status:
  • Normal—Antenna is detected (present) and there is no overcurrent.
  • Absent—Antenna is not detected.
  • Overcurrent—An overcurrent condition has been detected.
  • Unknown—Status reported while the module is initializing.
Leap Second Pending Read Boolean that returns True for up to 60 seconds before the leap second occurs, and cleared the second after the leap second occurs.
Note Note  The GPS satellites transmit the Leap Second information only once every 12.5 minutes. This property reports invalid values for up to 12.5 minutes after start-up. Use the UTC Offset Valid property to determine when this property starts returning valid values.
Leap Second Occurred Read Boolean that returns True starting the first second after the leap second occurs and remains True for 24 hours.
Note Note  The GPS satellites transmit the Leap Second information only once every 12.5 minutes. This property reports invalid values for up to 12.5 minutes after start-up. Use the UTC Offset Valid property to determine when this property starts returning valid values.
Leap Second Direction Read Returns Add or Delete depending on the kind of leap second event. Only valid when Leap Second Pending or Leap Second Occurred Properties are True. Disregard at other times.
Note Note  The GPS satellites transmit the Leap Second information only once every 12.5 minutes. This property reports invalid values for up to 12.5 minutes after start-up. Use the UTC Offset Valid property to determine when this property starts returning valid values.
Altitude (m) Read Return the current location coordinates in degrees and altitude in meters.
Note Note  The Altitude property reports altitude in meters HAE (height above ellipsoid).
Note Note  When the GPS receiver cannot compute a location fix during the self-survey (as reported by the GPS Status property), the location properties repeat the information obtained in the last successful location fix. When the self-survey is complete, the location properties return the precise location computed during the self-survey.
Latitude (°) Read
Longitude (°) Read
Satellites Available Read Returns the number of satellites the GPS receiver currently is tracking.
Firmware Read Returns the current GPS receiver firmware version.
Module ID Read Returns the module ID.
Serial Number Read Returns the unique module serial number.
Vendor ID Read Returns the National Instruments vendor ID, 0x1093.

Single-Cycle Timed Loop

This device does not support the single-cycle Timed Loop.

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