IBM EasyCoder 3400e Bar Code Label Printer User’s Manual, To check for communication problems

EasyCoder 3400e Bar Code Label Printer User’s Manual

Hardware handshaking uses pin 11 or pin 20 of the RS-232 interface to control data flow. When the printer is using Intermec Standard protocol, it holds pins 11 and 20 high when the printer is ready to receive data. The printer holds the pins low when the printer is in one of the following conditions:

•Buffer full

•Ribbon fault

•No label stock

•Label at strip bar

Your printer uses XON/XOFF protocol for software handshaking. When the input buffer is full, the printer transmits an XOFF character. The XOFF character alerts the host to the fact that the printer buffer is full and cannot receive any more data. When the printer is ready to receive more data, it sends the XON character.

The following procedure lists things to check to ensure that your printer and host system are communicating properly.

To check for communication problems

1.Check the cabling from the printer to the host system.

2.Check the interfacing of the devices that are communicating with the printer.

3.Check the printer for proper electrical operation of the I/O port.

4.Test to see that the host system is not overrunning the printer'’s input buffers.

5.Check to see that the data string being sent to the printer contains the correct information.

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