
Appendix C— Communications Reference
EasyCoder 4420 and 4440 Bar Code Label Printer User’s Manual
99
The parallel port conforms to the IEEE 1284 standard and it supports
Initialization, Compatibility Mode, Negotiation, Nibble, and Byte Mode
for reverse data transfer.
The serial port supports serial communications with the following
interfaces:
• RS-232
• RS-422
• RS-485
The following sections describe these interfaces. See the
Data
Communications Reference Manual
(P/N 044737) for more detailed
information.
RS-232 Serial Interface
Use the RS-232 serial interface in all asynchronous point-to-point full- or
half-duplex direct data communications or modem control. The printer
cable must have the pin assignments for an RS-232 serial interface shown
in the next table.
RS-422 Serial Interface
Use the RS-422 interface in long line point-to-point direct connect
installations. The printer cable must have the pin assignments for an RS-
422 serial interface shown in the next table.
RS-485 Serial Interface
Use the RS-485 serial interface for Multi-Drop installations only. The
printer cable must have the pin assignments for an RS-485 serial interface
shown in the next table.
RS-232, RS-422, and RS-485 Serial Interface Pin Assignments
Interface
Pin
Name
Operation
RS-232/422/485 1
Chassis
Ground
(GND)
Connect to pin 1, chassis ground, of connected device.
RS-232
2
Transmit Data
(TD)
Output: Connect to receive data pin of connected device.
RS-232 3
Receive
Data
(RD)
Input: Connect to transmit data pin of connected device.
RS-232/422/485
4
Request to Send
(RTS)
Output: When you use a modem, connect to modem RTS pin.
The connection sets RTS to true before transmission. The printer
sets RTS to false after transmission.
RS-232/422/485
5
Clear to Send
(CTS)
Input: When you use a modem, connect to modem CTS pin.
Modem must set CTS true before the printer transmits data. If not
connected, CTS sets itself true.