RS-232 Baud Rate Setup

To set the baud rate for the RS-232 port, set a general command code of 08. Set the function code to 01. Then set 3 control bytes as follows.

Function

Start

Control

Command

Function

UB3

Baud

Baud

Data

Check

 

of

Bytes

Code

Code

 

1

2

Bytes

Sum

 

Frame

 

 

 

 

 

 

 

 

Byte #

1

2

3

4

5

6

8

9

10

Value

01

05

08

01

 

 

 

00

 

Setting UB3

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Divisor

Set

Set

Even

Parity

Stop

Word

Word

Latch

Break

Parity

Parity

Enable

Bits

Length 1

Length 0

 

 

 

 

 

 

 

 

Bit 7 = 1 allows baud rate divisor to be changed. 0 baud rate change is blocked. Bit 7 should not be set. The setting and resetting of this bit is handled internally.

Bit 6 = 1 forces the transmitter output to a logic 0 for alerting the remote receiver to a line break. 0 indicates no break condition.

Bit 5, 4 and 3 work together to set parity

 

Bit 5

 

Bit 4

 

Bit 3

 

Parity Selection

 

*

 

*

 

0

 

No parity (default)

 

0

 

0

 

1

 

Odd parity

 

0

 

1

 

1

 

Even parity

 

1

 

0

 

1

 

Force parity “1”

 

1

 

1

 

1

 

Force parity “0”

 

 

*Don’t care state.

 

 

Bit 2, stop bit, works in conjunction with bits 1 and bit 0

 

 

 

 

 

 

 

Bit 2

 

Word Length (bits)

 

Stop Bit Length

 

0

 

5,6,7,8

 

 

 

 

1 (default)

 

1

 

5

 

 

 

 

 

1

 

6,7,8

 

 

 

 

2

 

 

 

 

 

 

 

 

 

HDV100A3 Command & Response Manual-1306cr

 

 

5

B&B Electronics -- 707 Dayton Rd. -- PO Box 1040 -- Ottawa, IL 61350

PH (815) 433-5100 -- FAX (815) 433-5104

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B&B Electronics HVD100A3 manual RS-232 Baud Rate Setup