Siemens Simatic S7-400 - Page 66

Baud Rate / Character Frame
The following table describes the transmission rate/character frame.
Table 5-12 Baud Rate / Character Frame (3964(R) Procedure)
Parameter Description Value Range Default Value
Baud rate Speed of data transmission in bits per second (baud)
• 300
• 600
• 1200
• 2400
• 4800
• 9600
• 19200
• 38400
• 57600
• 76800
• 115200
9600
Start bit During transmission, a start bit is pre󹪝xed to each character to be
sent.
1 (󹪝xed value)
Data bits Number of bits onto which a character is mapped.
• 7
• 8
8
Stop bits During transmission, stop bits are appended to every character to
be sent, indicating the end of the character.
• 1
• 2
1
Parity A sequence of information bits can be extended to include another
bit, the parity bit. The addition of its value ("0" or "1") brings the
value of all the bits up to a de󹪝ned status. This improves data
integrity.
A parity of "none" means that no parity bit is sent.
It is not possible to specify "none" if 7 data bits are set.
• none
• odd
• even
even
Priority A partner has high priority if its send request takes precedence
over the send request of the other partner. A partner has low pri‐
ority if its send request must wait until the send request of the
other partner has been dealt with. With the 3964(R) procedure,
you must con󹪝gure both communication partners with di󹪜erent
priorities, i.e. one partner is assigned high priority, the other low.
• low
• high
high
Con󹪝guring and Parameter Assignment the CP 440
5.4 Con󹪝guration data
Point-to-point connection CP 440 Installation and Parameter Assignment
66 Equipment Manual, 03/2022, A5E00057742-AE