DioGetInputLoadResistance

Applies To

GX5055, File

Purpose

Returns the channel input pull-up and pull-down resistive loads.

Syntax

DioGetInputLoadResistance (nHandle, nChannel, pdPullup, pdPulldown, pnStatus)

Parameters

Name
Type
Comments
nHandle
SHORT
DIO Master board handle, Board handle or File board handle.
nChannel
SHORT
If Board Handle was passed:
Channel number in the DIO board, each board has 32 I/O channels. I/O channels number range is 0-31.
If Master Board Handle was passed:
Channel number in the DIO domain, each DIO board adds 32 I/O channels. I/O channels number range is 0-991 (1 master and 30 slaves).
pdPullup
PDOUBLE
Input pull-up resistive loads can be one of the following:
  • DIO_RESISTIVE_LOAD_240_OHMS = 240
  • DIO_RESISTIVE_LOAD_290_OHMS = 290
  • DIO_RESISTIVE_LOAD_1K_OHMS = 1000
  • DIO_RESISTIVE_LOAD_OPEN = -1
pdPulldown
PDOUBLE
Input pull down resistive loads can be one of the following:
  • DIO_RESISTIVE_LOAD_240_OHMS = 240
  • DIO_RESISTIVE_LOAD_290_OHMS = 290
  • DIO_RESISTIVE_LOAD_1K_OHMS = 1000
  • DIO_RESISTIVE_LOAD_OPEN = -1
pnStatus
PSHORT
Returned status: 0 on success, negative number on failure.

Comments

Each channel has an independent load with the following capabilities:

0.  Channels’ Input constant source and sink currents up to 24 mA – DioSetupInputLoadCurrent  function.

1.    Maintain high impedance over a wide voltage.

2.    Separate high and low commutating voltages – DioSetupInputLoadCommutatingVoltage function.

3.    Channels’ Input Resistive load options - DioSetupInputLoadResistance function.

With independent high and low commutating voltages, the source and sink currents each have their own threshold voltage. If the voltage on the input, when the load is activated, is between the two commutating voltages, the load will remain in a high impedance state.

The input resistive load is useful in applications with very low DUT output swings (where a traditional active load will not switch on and off completely or quickly) and also as a means of forcing the DUT to a known voltage when the DUT is in HiZ.

NOTE: The source and sink currents should be programmed to 0 during normal operation of the resistive load.

When the resistive load is placed in HiZ (DIO_RESISTIVE_LOAD_OPEN) it maintains a low leakage current when the input voltage is between the supply rails.

Channels input pull-up and pull- down resistive loads can be read back and set dynamically at any time even while the DIO is running mode.

Example

The following example returns the input pull-up and pull down resistive loads for channel 0:

 

DOUBLE dPullup, dPulldown;

SHORT nStatus;

DioGetInputLoadResistance (nHandle, 0, &dPullup, &dPulldown, &nStatus);

 

See Also

DioSetupInputLoadState, DioSetupInputLoadCurrent, DioSetupInputLoadCommutatingVoltage, DioSetupInputLoadResistance, DioSetupInputThresholdVoltages, DioGetErrorString