Question

I need to send a series of printer commands to a Sato barcode printer. For example:

<ESC>A
<ESC>H0120
<ESC>V0060
<ESC>$B,180,180,0
<ESC>$=Information
...

I have an open tcp/ip connection to the printer and simply want to write an NSData object, such as:

[connection write:data error:error];

wheras data is an NSData object. I realize that I can insert the escape into a string using the binary value with \x1B. For example:

NSString *printString=[[NSString alloc]initWithString:@"\x1BA\X1BH0120\X1BV0060\X1B$B,180,180,0/X1B$=Information"];  

The problem I’m having is that I don’t know how to translate my string to NSData for the write.

I appreciate any suggestions.

Answer 1

I’ll give an update on some of my findings in case someone stumbles upon a similar problem in the future. My problem was that I needed to send a series of printer commands to a Sato barcode printer. Sato uses a proprietary language that requires syntax like above whereas I needed to send commands like <ESC>A and <ESC>Z. I had an open tcp/ip connection and kept trying several methods to send the commands with no luck. I though the problem was in my translation to NSData. I was close, but not close enough. The problem turned out to be in my translation from a file to an NSString…not when I was converting the NSString to NSData. I also had problems trying to use \x “escapes” to send the binary equivalent of <ESC>. I finally settled on using the octal equivalent.

    // load the appropriate file as a string
    NSString *filePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"sato.txt"];
    NSError *firstError=nil;
    NSString *satoData=[[NSString alloc]initWithContentsOfFile:filePath encoding:NSNonLossyASCIIStringEncoding error:&firstError]; // the NSNonLossyASCIIStringEncoding was the key to correcting my problem here.
    satoData=[satoData stringByReplacingOccurrencesOfString:@"Description" withString:self.description];
    satoData=[satoData stringByReplacingOccurrencesOfString:@"ItemID" withString:self.itemId];
    satoData=[satoData stringByReplacingOccurrencesOfString:@"Quantity" withString:self.printQty];
    NSDate *now=[NSDate date];
    NSString *formattedDate=[NSDateFormatter localizedStringFromDate:now dateStyle:NSDateFormatterMediumStyle timeStyle:NSDateFormatterNoStyle];
    satoData=[satoData stringByReplacingOccurrencesOfString:@"Date" withString:formattedDate];
    NSData *data=[satoData dataUsingEncoding:NSUTF8StringEncoding];

    [connection write:data error:error];

Here is a sample of some of the contents of the sato.txt file

\033A\033#E5\033Z
\033A\033H0120\033V0060\033$B,180,180,0\033$=ItemID

The \033 is the octal escapes for <ESC>