Printronix T3306 - Manual (Page 115)

4–3 Diagnostics and Troubleshooting
The time required varies, depending on the complexity of the label format and on
the size of the area being printed. Once the data has been mapped into memory,
the printer will start printing as many labels as requested by the quantity
command. In most cases, there is no delay between labels; however, there are
certain situations that may cause delays between label printing:
•
Using the cutter option
The printer must stop and wait for the cutter to execute the cutting cycle.
•
Using the Automatic Label Peel-Off option
The printer stops between each label and waits for the label to be
removed.
Data Exchange
Many things can cause data loss or communications problems. This section
suggests some ways to isolate these problems and determine their cause.
Handshaking
Handshaking is the exchange of signals between two computers (or a computer
and a peripheral input or output device) to indicate the status of the data being
transferred. In the serial mode, the printer uses both hardware and software
handshaking and transmits both forms simultaneously when the input buffer is
full.
The printer can be used with either serial or parallel host interfaces. Parallel
interfaces are usually straightforward, with no special settings required. Serial
interfaces, however, have a variety of possible communication parameter
settings. The two methods of handshaking that can be used, hardware and
software, are explained below.
•
Hardware Handshaking
This electrical signal is controlled by the logic state on pin 20 of the serial
interface connector J2 (at the back of the printer). The signal will go high
when the printer is ready to receive data. The signal will go low 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.