TEK-CPCI-1000 Technical Reference Manual
7-6
RS-422 Protocol:
The RS-422 protocol (Full Duplex) uses both RX and TX lines during a communication
session. Upon a power-up or reset, the Serial Port 2 interface circuits are automatically
configured for full duplex operation: pins 3 and 4 of Serial Port 2 act as receiver lines while
pins 5 and 6 act as transmitter lines.
Internal circuit may be represented as follows:
3
5
R X-
TX-
4
6
R X +
TX +
120 ohm s
120 ohm s
SER IAL PO R T 2
10-P IN HEA D ER
R X D 2
G N D
V C C
TX D
X
X
1
1
2
2
LO W LO G IC LEV E L
LO W LO G IC LEV E L
7
7
6
6
3
3
4
4
There are no user software restrictions except that software must not attempt to use the
handshake line because they are not connected. However, handshaking by software only
(XON-XOFF) may be used.
CAUTION
When working in RS-422 protocol, W6 and W7 jumper caps must be
installed to connect the 120 ohms termination resistors (See Section 10 -
Jumper Settings).
Summary of Contents for TEK-CPCI-1000
Page 12: ...TEK CPCI 1000 Technical Reference Manual 1 4 TEK CPCI 1000 CompactPCI Block Diagram...
Page 59: ...Setting Jumpers 10 3 10 2 CPU MODEL SELECTION W1 AND W2...
Page 116: ...C 1 C BOARD DIAGRAMS C 1 MECHANICAL SPECIFICATIONS...
Page 117: ...TEK CPCI 1000 Technical Reference Manual C 2 C 2 ASSEMBLY TOP DIAGRAM...
Page 118: ...Boards Diagrams C 3 C 3 ASSEMBLY BOTTOM DIAGRAM...
Page 141: ......
