Microsoft UNO-3074 user manual RS-232 Interface COM1~COM2, RS-232/422/485 Interface COM3~COM4

2.2 RS-232 Interface (COM1~COM2)

The UNO-3074 offers two industrial standard RS-232 serial communica- tion interface ports: COM1 and COM2. Please refer to Appendix A.4 for their pin assignments.

The IRQ and I/O address range of COM1 and COM2 are listed below:

COM1: 3F8H, IRQ4 COM2: 2F8H, IRQ3

2.3 RS-232/422/485 Interface (COM3~COM4)

The UNO-3074 offers two industrial RS-232/422/485 serial communica- tion interface ports: COM3 and COM4. Please refer to Appendix A.5 for their pin assignments. The default setting of COM3 and COM4 are RS- 422/485. (Please refer to section 2.3.4 for how to determine RS-232 or RS-422/485)

2.3.116C550 UARTs with 16-byte FIFO Standard

Advantech UNO-3074 comes with 16C550 UARTs containing 16 bytes FIFOs.

2.3.2RS-422/485 Detection

In RS-422/485 mode, UNO-3074 automatically detects signals to match RS-422 or RS-485 networks. (Refer to section 2.3.5)

2.3.3 Automatic Data Flow Control Function for RS-485

In RS-485 mode, UNO-3074 automatically detects the direction of incom- ing data and switches its transmission direction accordingly. So no hand- shaking signal (e.g. RTS signal) is necessary. This lets you easily build an RS-485 network with Data+, Data- and Ground. More importantly, appli- cation software previously written for full-duplex RS-232 environments can be maintained without modification.

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