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MashaCPAFlag for United States of America

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Serial Printer is Very Slow; Often Cannot Print Until Computer is Rebooted

I have a serial thermal receipt printer.  The higher the volume of printing, the more often it stops printing, and I have to reboot the computer and print all the jobs stuck in the memory.  If I change the COM1 speed to higher than 9600, only garbled stuff comes out.

Will a serial-to-parallel converter help?  Any other suggestions?

Urgent pls.
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hdhondt
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If you change the baudrate on the PC you have to also change it on the printer - otherwise the printer won't understand the data, and will indeed print garbage. Note that 9600 baud sends around 960 characters per second to the printer - I doubt it can print that fast, so higher speeds would not help anyway.

Try setting the port to either Xon/Xoff or hardware flow control. Go to Start > Settings > Printers. Right-click on the printer and select Properties. Then click on the Ports tab, and then on the Configure Port button (this is also where you change the baudrate)

Can you test the printer on another system? it can be failing also.
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Watzman

What interfaces does the receipt printer have?  Serial, obviously, but does it have parallel or USB?  Either would be a lot faster than serial.

What kind of system are you using this printer on?

Are you printing graphics or only straight text?
(note, text printed as a graphic is graphics, not text)

Thermal printers are normally speed rated in "inches (of paper) per second" (sometimes given in metric mm/second instead of inches), not in charaters per second.  Normally, a receipt has a very small number of characters on, just a couple hundred, and even serial, even at speeds lower than 9600 baud, is fast enough to easily keep up with anything that you are going to print in text mode.  In grahics mode, however, that might well not be the case.

It's possible that the printer's printhead is overheating and that it's "thermal throttling" to keep from overheating the printhead.  This would only be an issue at high volume.  Thermal receipt printers are designed to print a receipt, then pause for a relatively long period of time (in relation to the time required to print a receipt), then print, then pause, etc.  If you are trying to print a large volume, and not short receipts of only a few inches before a [relatively] long pause, this may be what's happening; you may be trying to use the printer in a mode for which it was not intended.

[however, you should not have to reboot; the printer should resume printing after a pause]


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I changed it from Xon/off to Hardware flow control and also from Spool to Print Directly to Printer this morning.  No change.

After rebooting, it prints a couple of receipts normally and then just does not respond to a print command at all until the computer is rebooted.  Usually, there is at least a couple of minutes delay between serving one customer to the next; usually even more.

This is an Emachines Windows 98 PC with 256 MB RAM; it was bought a few years ago.
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Watzman

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Ok, the serial port setup is done in Device manager, I think, and it has an option for XON/XOFF, so that may be the easiest way to go.  For that you will need a cable configuration that will let the printer send data to the comptuer, as well as the computer sending data to the printer.  You would need to select XON/XOFF both in the serial port configuration (Control Panel / System / Device Manager / Ports / select the proper serial port, right-click, properties, and it's done in one of the tabs, the same tab where you set the buad rate).