Serial interface, Figure 3-1, Rs-485 serial port implementation – ADLINK CoreModule 430 User Manual
Page 27
Chapter 3
Hardware
CoreModule 430
Reference Manual
21
Serial Interface
The Vortex CPU contains the circuitry for all four serial ports. The CoreModule 430 provides serial ports 1
and 2 through transceivers U7 and U9 (headers J3 and J9), serial port 3 through transceiver U4 (header J14)
and serial port 4 through transceiver U5 (header J13). The serial ports support the following features:
•
Programmable word length, stop bits and parity
•
16-bit programmable baud rate generator
•
Interrupt generator
•
Loop-back mode
•
16-bit FIFOs for each port
•
Ports 1, 2, 3, and 4 are supported by the Vortex processor and are 16C550/16C552 compatible
Serial 1 (J3, COM1) supports RS-232/RS-485 with full modem operation
Serial 2 (J9, COM2) supports RS-232/RS-485 with full modem operation
Serial 3 (J14, COM3) supports RS-232 with full modem operation
Serial 4 (J13, COM4) supports RS-232 with full modem operation
To implement the two-wire RS-485 mode on either serial port, you must tie the equivalent pins together for
the selected port.
For example, you must tie pin 3 (Rx Data –) to 5 (Tx Data –) and pin 4 (Tx Data +) to 6 (Rx Data +) at Serial
Port 1 or 2 (J3 or J9) for the two-wire interface. As an alternate, you may short the equivalent pins on the
DB9 connector attached to respective serial port, as shown in
. Refer also to the following tables
for the specific pins on the connectors. The RS-422 mode uses a four-wire interface and does not require
combining pins for its operation, but you must select RS-485 in BIOS Setup.
Figure 3-1. RS-485 Serial Port Implementation
provides the signals for the corresponding pins of the two independent serial interfaces (Serial 1 &
2), and
provides the signals for the corresponding pins of two independent serial interfaces (Serial
3 & 4). Both interfaces use 10-pin, right-angle headers with 2 rows, odd/even sequence (1, 2), and 0.100"
(2.54mm) pitch.
NOTE
The RS-232/RS-485 mode for Serial Port 1 (COM1) and Serial Port 2 (COM2)
are selected in BIOS Setup Utility. However, the RS-232 mode is the default
(Standard) for any serial port.
RS-485 mode termination is selected with jumper JP2 Serial 1 (COM1) and JP1
Serial 2 (COM2) on the module. Refer to
for more information.
CM430RS485jump_b
Or
1
3
5
7
9
2
4
6
8
10
Serial Ports (J3, J9)
(COM1 or COM2)
Side View
Standard DB9 Serial
Port Connector (Female)
Rear View
5
4
3
2
1
9
8
7
6