Kontron ePCI-101, User Manual, Page: 38 / 109

2-15
ePCI-101 User’s Guide
CAUTION
In RS-422 mode, JP5 and JP6 jumper caps must be installed to connect the
120-ohm line termination resistors.
RS-485 Protocol
During a communication session, the RS-485 protocol (Full Duplex) uses differential signals. It differs
from the RS-422 mode by offering the ability to transmit and receive over the same pair of wires and
allows the sharing of the communication line by multiple stations. This configuration (also known as
Party Line) allows only one system to take control of the communication line at the time.
In RS-485 mode, the RX lines are used as the transceiver lines and the RTS signal controls the
direction of the RS-485 buffer.
When set for RS-485 mode in the BIOS, upon power-up or reset, the transceiver is set by default in
receiver mode to prevent unwanted disturbance on the line. The operation mode for party lines
requires termination resistors to be installed at both ends of the network.
CAUTION
When installing the board at one end of the network, JP5 and JP6 jumper caps
must be installed to connect the 120 ohms termination resistors.
(See
Setting Jumpers ).
2.4.4 Parallel Port (J6)
The board features one IEEE-1854 multi-mode parallel port. It is compatible with Standard Mode
IBM PC/XT, PC/AT, and PS/2 compatible bi-directional parallel port, Enhanced Parallel Port (EPP),
and Enhanced Capabilities Port (ECP).
Pin Signal Pin Signal
1 STB# 2 ALF#
3 D0 4 ERR#
5 D1 6 INIT#
7 D2 8 SLCTIN#
9 D3 10 GND
11 D4 12 GND
13 D5 14 GND
15 D6 16 GND
17 D7 18 GND
19 ACK# 20 GND
21 BUSY 22 GND
23 PE 24 GND
25 SLCT 26 GND