
E
Uses the next 6 characters in the format to briefly display a message on the front
panel.
Q
Causes the following printing to be sent to the duplex port and continue until a 'Q' is
again received. For example, "\Qdata\Q".
1
Causes the 4200 to print the contents of the receive buffer. This is useful for
applications such as bar code readers. The bar code information can be sent to the
duplex port from the bar code reader (must be followed by a carriage return), and
the label format could be set up to print this information in a specific format (usually
used with a special printer, such as the Prodigy printer). A limitation of this feature
is that if a string is sent to the 4200 and it recognizes it as a valid command, it will
act on it, so only
strings that are non-valid commands should be sent.
PORT 2 - SIMPLEX
Port 2 is a simplex (one-way) port, meaning that it can only send data, not receive. It is
normally used as printer port, and can be connected to virtually any printer or other data
collection device. The way that a print is initiated is controlled by setup parameter 4 (Serial
Data Output), and the format of the printout is controlled by setup parameters 15 (Print
Format), 24 (Time and Date Output), and 25 (Line Feed and Form Feed).
As with the duplex port (port 1), port 2 can be ordered with a data cable and DB9 or DB25
connector. If a connector is ordered, the wiring requirements for your printer must be
specified since they vary among printer manufacturers. The main board port wiring
connections are shown in Section 12. Note that a shielded cable must be used to
eliminate interference from other equipment.
Port 1 can be configured for RS232 or 20 mA current loop operation. As explained in the
PORT 1 section, RS232 is the most common interface in the computer industry, but the 20
mA current loop allows much longer cables to be used.
The baud rate, data bits, and parity settings of the 4200 must match those of the printer or
other equipment that is to be connected to port 2. The 4200 comes standard with the most
common settings which are: baud rate = 9600, data bits = 8, parity = n. These can be
changed to match the printer (see Section 5, parameters 13a and 14a), or the printer
settings can be changed to match those of the 4200.
The 4200 also has an option setting to enable or disable handshaking (see Section 6,
parameter 19). This refers to the CTS (Clear to Send) signal that many printers use. If the
handshaking is enabled for port 1, the CTS line must be connected from the main board to
the printer. This line is supplied if a cable is ordered (see Section 12 for connections).
Section 8 Serial Communications
62