GxCntGetCounterRefClockToPxiRefClockState

Applies To

GTX2220, GTX2230

Purpose

Returns the connection state of the Counter Reference Clock to the PXI Reference Clock.

Syntax

GxCntGetCounterRefClockToPxiRefClockState (nHandle, pnState, pnStatus)

Parameters

Name
Type
Description
nHandle
SHORT
Handle to a counter board.
pnState
PSHORT
Returned the Counter Reference Clock to PXI Reference Clock state:
  • 0 = GXCNT_CLOCK_TO_PXI_REF_CLOCK_OFF: Disconnect the Counter Reference Clock from the PXI Reference Clock.
  • 1 = GXCNT_CLOCK_TO_PXI_REF_CLOCK_ON: Connect the Counter Reference Clock from the PXI Reference Clock.
pnStatus
PSHORT
Returned status: 0 on success, negative number on failure.

Comments

The PXI chassis has a 10 MHz clock line (PXI_CLK10) in its backplane that allows devices plugged into the non-star controller slots (slots 3 and higher) to phase-lock their oscillators to the backplane clock. A single backplane clock can control this way the drift in the oscillators on all the devices in the non-star controller slots. The GTX2220/30 board when plugged into the star-controller slot (slot 2) can replace the PXI backplane clock with its much more stable oscillator. Alternatively, when plugged into one of the non-star controller slots (slots 3 and higher), the GTX2220/30 board can be programmed that its clock source will use the PXI backplane clock see the GxCntSetClockSource function for details.

This call is valid only if the GTX2220/30 board is plugged into the star-controller slot (slot 2) of the PXI chassis.

Example

The following example returns the connection state of the Counter Reference Clock to the PXI Reference Clock:

 

SHORT nState;

GxCntGetCounterRefClockToPxiRefClockState (nHandle, &nState, &nStatus);

 

See Also

GxCntSetCounterRefClockToPxiRefClockState, GxCntSetClockSource, GxCntGetClockSource, GxCntGetErrorString