Moxa DA-681-I-DP-LX [30/47] Serial port configuration

DA-681-CE Series WinCE User’s Manual Management Tools

Serial Port Configuration

The DA-681-CE has 12 serial ports. Ports 1 to 4 support the RS-232 interface, whereas ports 5 to

12 support the RS-485 2-wire interface. See the following figure for detailed information.

Non-standard baudrates

Moxa’s UART ASIC supports most non-standard baudrates in the range 50 bps to 921.6 Kbps. In

fact, supported baudrates are much denser towards the lower values. For example, no baudrates are

supported between the integers 5320 and 5323, but 49 baudrates are supported between the

integers 387 and 388. Of course this is the way it should be, since serial devices that require using

non-standard baudrates generally use slower baudrates.

Before using a serial device that requires using a non-standard baudrate, you must first check that

the DA-681 supports a baudrate within the tolerance specified by the serial device manufacturer.

Use the following formula to calculate which baudrates are supported by the DA-681:

(A) Baudrate = 921600/(N+M/8) bps, for N = 1, 2, …, 18431, M = 0, 1, 2, …, 7

(B) Baudrate = 8 x 921600/K bps, for K = 8, 9, …, 147456

If you are a programmer and you need to write a driver for your serial device, then you may need

to use formula A. If you have a serial device that requires using a non-standard baudrate, then you

can use formula B to determine if the DA-681 supports a baudrate within the tolerance specified

by the serial device manufacturer.

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