How to Display Text and Clear the Text of Partner CD7220-UN Customer Display / Pole Display

Question

I have a Partner Tech CD7220-U 1.0 Customer Display and I'm trying to develop a POS system using C#. I need to show the unit price and Total Amount using the customer display. So I have searched the google and found few solutions to show the text on the display. here are the links I followed,

1)http://www.codeproject.com/Questions/67846/How-to-display-text-on-USB-Posiflex-Customer-Displ

2)http://www.codeproject.com/Tips/658377/PartnerTech-CD-POS-Customer-Display-NET-Class

In the example (1)

    using Microsoft.PointOfService;

private const string WelcomeMessage = "Welcome\r\n";
private PosExplorer posExplorer;
private LineDisplay posLineDisplay;
private DeviceInfo posLineDisplaydevice;

public void LineDisplayUnit()
{
this.posExplorer = new PosExplorer(this);
this.posLineDisplaydevice = this.posExplorer.GetDevice("LineDisplay", "POSIFLEX_LINEDISPLAY");

try
{
this.posLineDisplay = (LineDisplay)this.posExplorer.CreateInstance(this.posLineDisplaydevice);
this.posLineDisplay.Open();
this.posLineDisplay.Claim(1000);
this.posLineDisplay.DeviceEnabled = true;
this.posLineDisplay.DisplayText(WelcomeMessage);
this.posLineDisplay.DisplayTextAt(2, 1, this.LeftAlign("Amount", 7) + this.RightAlign(this.GrandTotalAmount.ToString("0.00"), 12));
this.posLineDisplay.Close();

}
catch (Exception)
{

}
}

I have the following exception

In example to I'm able to send the Text to the Customer Display. but I'm unable to clear the screen.

Here's the code

public void WriteSomethingRedToPrinterThroughDisplay()
    {
        cUSB.OpenPort(); // Open the USB Port
        cUSB.WritePort(Strings.Chr(12));   // Clear pole display
        cUSB.WritePort(Strings.Chr(27) + Strings.Chr(61) + 
        Strings.Chr(1));   // Send print through pole display
        cUSB.WritePort(Strings.Chr(27) + Strings.Chr(64));   // Initialize printer
        cUSB.WritePort(Strings.Chr(27) + Strings.Chr(114) + 
        Strings.Chr(1));   // Select Red color to print
        cUSB.WritePort(string.Format("{0,-10}{1,7:-0.000}
        {2,10:0.00}{3,13:-0.00}", tempitemid, tempunits, 
        tempunitprice, tempsubtotal) + Strings.Chr(10));   // Print text and new line
        cUSB.WritePort(Strings.Chr(27) + Strings.Chr(114) + 
        Strings.Chr(0));   // Set color to default Black
        cUSB.WritePort(Strings.Chr(27) + Strings.Chr(61) + 
        Strings.Chr(2));   // De-select printer and enable pole display
        cUSB.ClosePort();  // Close the USB Port
    }

Please send me the correct tutorial or correct method to show text in the display unit. your help will be highly appreciated.

Answer 1

Use the second link that you have mentioned above.

You can use public class USBas it is. Use cUSB.WritePort("\f") to clear the pole display.

private void button1_Click(object sender, EventArgs e)
{
cUSB.OpenPort(); // Open the USB Port
cUSB.WritePort("\f"); // Clear pole display
cUSB.ClosePort();
} 

I think the following codes will also be useful to you.

\f - clear screen

\n - new line with tab

\r - next line

\t - tab

\v - first row first column