Verifone vx520 change printer font

Question

I want to change the Verifone vx520 internal printer font. I have written my program in C and I used the Font Designer Tool for creating the printer font. I have used the <ESC>m<s><t> command to download font table but I still can't change the printer's font. How can I do it?

Answer 1

Rather than using the straight escape sequences, you may consider using the "p3700_" functions on a 520. Specifically, you will want p3700_dnld_font_file() and p3700_select_font().

According to the documentation:

#include <printer.h>
short p3700_dnld_font_file(short handle, //the open printer handle
short h_font_file, //the open file handle
short font_table //font table to select
);

short p3700_select_font(short h_comm_port, // the open printer handle
short font_size, // size of the font
short font_table // font table to select
);

The documentation also has this as part of an example program (modified slightly):

//Variable declarations
int handle; // file handle for the Printer
open_block_t parm; // structure to fill comm parameters for com port
int h_font_file; // handle to the font file

//open printer
handle = open("/dev/com4", 0);

//initialize printer
memset(&parm,0,sizeof(parm));
parm.rate = Rt_19200; // ITP is always set to 19200 baud
parm.format = Fmt_A8N1 | Fmt_auto |Fmt_RTS; // ITP is always set at 8N1
parm.protocol = P_char_mode;
parm.parameter = 0;
set_opn_blk(handle, &parm);
SVC_WAIT(200);
p3700_init(handle, 6);
SVC_WAIT(100);

// Download a 16x16 printer font file containing 128 chars from offset 0 to 127
h_font_file = open("16x16.pft", O_RDONLY);
// download the printer font file at font table 1
p3700_dnld_font_file (handle, h_font_file, 1);
strcpy((char *)printBuf,(const char *)"Printing 16x16 Font\n\n");
p3700_print(handle, printBuf);
p3700_select_font(handle, 0x01, 1);
// 0x01 corresponds to 16x16 font size
p3700_print(handle, printBuf);

I have tested this with both p3700_ print functions and p3300_ functions and they both seem to work fine. A few notes for troubleshooting:

1. Make sure to have #include <printer.h> in your code
2. When saving the font file, select the correct printer type. If you are using p3700 function calls, save as a "Verix 37xx" printer type. If you are using p3300 calls, then save as "Verix 33xx".
3. If you are copying the example code, you'll need to make sure your custom font size is 16x16 and that you save it to font table 1 (select the font table on the same dialog where you select the printer type). If you do something different, you'll need to change p3700_select_font accordingly.
4. Be sure to remember to download the font to the terminal.
5. Check the return values of function. For example, open should return a positive file handle number and p3700_dnld_font_file should return the number of font characters that were downloaded, etc.

Here is a similar question and answer regarding printing graphics.

---

If you want to stick with escape sequences, I'm not sure where you are getting <ESC>m<s><t> from. 23230_Verix_V_Operating_system_programmers_Manual shows:

<ESC>m<c><r1>...<rn>; Downloads fonts into memory.

and then

<ESC>l<s><t>; Selects font table for printing and downloading.

Personally, I tend to avoid the escape sequences for everything other than toggling double wide, double height and inverse.