Data Exchange
The signals will go either low or high, depending on the configuration setting, when the printer is in the busy state, which indicates that the printer input buffer is full and can no longer receive data.
•Software Handshaking
XON and XOFF are software signals that control serial data flow between the printer and the host system. When the printer input buffer is full, the printer transmits an XOFF (CTRL S) character that signals the host to stop sending data. When memory space becomes available in the input buffer, the printer sends an XON (CTRL Q) character, which tells the host that the printer is ready to receive more data.
If the printer appears to have communication problems, the
Both of these test procedures are covered in this chapter. Configuration items to check include the following:
•Check that the data string being sent to the printer contains the correct information.
•Verify that the correct host interface port is being used and that the communication parameters match those of the host (i.e., baud rate, parity, etc.).
•Verify that the correct interface cable is installed between the host and the printer.
Interfacing
The printer will not function properly with an incorrectly wired cable or the wrong interface cable installed. If the cable is suspect, contact Printronix or your authorized service representative.
When the printer is first powered up, it will reset itself to the communication default parameters. The parameters are listed in the following table:
PARAMETER | DEFAULT VALUE |
|
|
Baud | 9600 |
|
|
Data Bits | 8 |
|
|
Parity | NONE |
|
|
Stop Bits | 1 |
|
|
The printer configuration settings may be entered through the main menu HOST INTERFACE function, which is accessed through the secondary control panel. (See Chapter 3, “Configuring the Printer” for complete instructions.)
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