PCM-C418/Configuration
v1.0
www.winsystems.com
Page 24
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485TE - Selects the Transmit Enable signal in RS-422/485 mode; 1=TXD enable,
0=RTS enable
Default = 0 = RTS enable
•
SLEW - Limit slew rate to 250 kbps
Default = 0 = Max data rate
•
TERM - Enables RS-422/485 terminations
Default = 0 = Disabled
•
EN - Enables the SP339 multimode UART
Default = 1 = Enabled
MODE - Selects the communication mode of the serial port (set in BIOS and should be
maintained).
Example:
Set COM1 to RS-485 Auto with termination and COM2 RS-422 Auto with
SKEW:
Write 0x00 to 0x1E9
Points to COM1-2 Mode controls
Write 0x2E to 0x1EA
COM1 - 485TE, TERM2, EN1, MODE 2
Write 0x37 to 0x1EB
COM2 - 485TE, SLEW2, EN2, MODE 3
LPT [DB25 Female]
The LPT port is a multimode parallel printer port that supports the PS/2 standard
bidirectional parallel port (SPP), enhanced parallel port (EPP), and extended capabilities
port (ECP) functionality. The output drivers support 8 mA per line.
The printer port can also be used as two additional general-purpose I/O ports if a printer
is not required. The first port is configured as eight input or output only lines. The other
port is configured as five input and three output lines.
Table 14:
Modes
Mode
Description
0
LOOPBACK
1
RS232
2
RS485
3
RS422
