Elo TouchSystems 1525L manual Interacting with the device, ‘open the port for binary access

Section 1. Overview

Settings tab. This gives both the Friendly Name and the port name (COM<5-15>). It also identifies the physical port that will be used to communicate with the device.

Open the device using either of the previous names. Use whatever facility is provided by your development environment for opening files. For Visual Basic, do the following:

'set error handling On Error Resume Next

‘open the port for binary access

Open “\\.\micr+” For Binary Access Read Write As #1 If Err.Number <> 0 Then

<<process error>> End If

on error goto 0

Note

The friendly name of the device, as found in the operating system’s device UI (Device Manager in Windows 95, for example), must be prefixed with “\\.\” in order to open the device. If the previous example did not have the prefix, it would create a file named micr+ in the current directory–clearly not the desired result.

Interacting with the device

An application interacts with the device by sending commands to the device and reading its responses. Commands are sent by writing to the opened port and responses from the device or property requests are retrieved by reading from the port.

To interact with the device using the MSComm component, invoke a command by assigning it to MSComm’s Output property. The response is received by MSComm’s OnComm event handler as a comEvReceive event or by directly polling the port. The entire response to a command or property request is received as a single event.

'submit echo command

Comm.Output = "/echo Hello" + Chr$(10)

Private Sub Comm_OnComm()

‘return if not a receive event

If Comm.CommEvent = comEvReceive Then

‘process received data

a$ = Comm.Input	‘get echo data
Else

<<process non-read event>> End If

End Sub

If using file I/O access, interaction with the device is indistinguishable from writing to or reading from a file.

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