# DBitIn()

Reads the state of a single digital input bit.

This method treats all of the DIO ports of a particular type on a board as a single port. It lets you read the state of any individual bit within this port. Note that for some port types, such as 8255 ports, if the port is configured for DigitalOut, this method provides readback of the last output value.

Refer to the "Digital Input/Output Hardware" topic for additional details on using the UL digital I/O methods.

Member of the MccBoard class.

## Function Prototype

VB .NET

Public Function DBitIn(ByVal portType As MccDaq.DigitalPortType, ByVal bitNum As Integer, ByRef bitValue As MccDaq.DigitalLogicState) As MccDaq.ErrorInfo

C# .NET

public MccDaq.ErrorInfo DBitIn(MccDaq.DigitalPortType portType, int bitNum, out MccDaq.DigitalLogicState bitValue)

## Parameters

portType

There are three general types of digital ports — ports that are programmable as input or output, ports that are fixed input or output, and ports for which each bit may be programmed as input or output. For the first of these types, set PortType to FIRSTPORTA. For the latter two types, set PortType to AUXPORT. For devices with both types of digital ports, set PortType to either FIRSTPORTA or AUXPORT, depending on which digital inputs you wish to read.

bitNum

Specifies the bit number within the single large port.

bitValue

Placeholder for the return value of the bit. Value will be 0 (logic low) or 1 (logic high). Logic high does not necessarily mean 5 V – refer to the device hardware user guide for chip input specifications.

## Returns

- An ErrorInfo object that indicates the status of the operation.
- BitValue – value (0 or 1) of the specified bit.