InitPorts (and variations)

Initialize device, ports

Description:

This is a function that initializes both ports and resets the device’s internal latches.

There are two 8-bit ports on the U401⁄421⁄U451, 16 I⁄O lines. The 16 total I⁄O lines can be set to inputs or outputs on an individual per-line basis. The initial state of the ports on power up is that all of the 16 lines are set to be inputs.

Command Syntax: (USBm.dll)

USBm_InitPorts( device )

The USBm_InitPorts function syntax has these parts:

Part	Description
device	A zero-based index to address the appropriate USB device.

Remarks:

Calling USBm_InitPorts will reset the ports to input and will clear the internal latches.

Calling USBm_InitPortsU401 will reset the ports to input and will clear the internal latches.

Calling USBm_InitPortsU421 will reset the ports to input and will clear the internal latches.

Calling USBm_InitPortsU451 will reset port A to input, port B to output and will clear the internal latches.

There is nothing stopping you from calling the USBm_InitPortsU421 when connected to a U401, for instance. Or any of the other combinations. The different flavors of init are provided for user convenience. USBm_InitPortsU451 is currently the only different one in the group as it sets port B to all output.

USBm_InitPorts is in all versions of the DLL. The variations are present in version 65 or newer.

VB Declaration

Public Declare Function USBm_InitPorts _
    Lib “USBm.dll” _
        (ByVal device As Byte) _
   As Integer

Public Declare Function USBm_InitPortsU401 _
    Lib “USBm.dll” _
        (ByVal device As Byte) _
   As Integer

Public Declare Function USBm_InitPortsU421 _
    Lib “USBm.dll” _
        (ByVal device As Byte) _
   As Integer

Public Declare Function USBm_InitPortsU451 _
    Lib “USBm.dll” _
        (ByVal device As Byte) _
   As Integer

VB Example

USBm_InitPorts (3)

This code fragment initializes the ports of device number three.

C Prototype

int USBm_InitPorts( unsigned char device );
int USBm_InitPortsU401( unsigned char device );
int USBm_InitPortsU421( unsigned char device );
int USBm_InitPortsU451( unsigned char device );

C Example

USBm_InitPorts( 0 );

This code fragment initializes the ports of device number 0 (the first U4x1 device that is found).

RobotBASIC

usbm_InitPorts(ne_DeviceNumber)

Returns true if successful, false otherwise. This function resets the A and B ports as Input Ports, which is the default state upon connecting the device to the PC.

Raw Command Format:

Byte Number	Description
0	00h: InitPortsCmd
1	<not used>
2	<not used>
3	<not used>
4	<not used>
5	<not used>
6	<not used>
7	<not used>

Raw Command Format Details:

Byte 0 contains the command. Byte 1 through byte 7 are unused.

Raw Command Response Format:

Byte Number	Description
0	00h: InitPortsCmd
1	<not used>
2	<not used>
3	<not used>
4	<not used>
5	<not used>
6	<not used>
7	<not used>

Raw Command Response Format Details:

Byte 0 contains the command. Byte 1 through byte 7 are unused.

Raw Command Example Usage:

Sending the InitPortsCmd command to the device will reset the ports.