UNO-1170A/AE User Manual 10
2.2 COM1~COM2: RS-232 Interfaces
The UNO-1170A/AE offers two standard RS-232 serial communication
interface port on COM1 and COM2. Please refer to A.2 for pin assign-
ments.
2.3 COM3: RS-232/422/485 Interfaces
The UNO-1170A/AE offers one RS-232/422/485 serial communication
interface ports. The serial communication can be configured to either RS-
232, RS422/485 by using on-board jumper. Please refer to A.3 for pin
assignments and Table 2.1 lists the default setting of each port.
2.3.1 TI 16C550 UARTs with 16-byte Standard
Advantech UNO-1170A/AE comes standard with TI 16C550 UARTs
containing 16 bytes FIFOs. These upgraded FIFOs greatly reduce CPU
overhead and are an ideal choice for heavy multitasking environments.
2.3.2 Jumperless RS-422/485
In RS-422/485 mode, UNO-1170A/AE automatically sense signals to
match RS-422 or RS-485 network. No need to change jumpers.
2.3.3 Automatic Data Flow Control Function for RS-485
In RS-485 mode, UNO-1170A/AE automatically senses the direction of
incoming data and switches its transmission direction accordingly. There-
fore no handshaking signal (e.g. RTS signal) is necessary. This feature
lets you simply and quickly build an RS-485 network with just two wires.
More importantly, application software previously written for half duplex
RS-232 environments can be maintained without need for modification.
Table 2.1: COM3 Default Settings
COM Port Default Setting
COM3 RS-422/485
