Siemens LMV3 series, Технические инструкции, Страница: 163 / 224

LMV Series Technical Instructions
Document No. LV3-1000
SCC Inc. Page 3 Section 7
Temporal process of communication
Both beginning and end of a data block are characterized by transmission pauses. Between 2 successive
characters, a maximum period of 3.5 times the character transmission time may elapse. The character
transmission time (time required for the transmission of one character) is dependent on the Baud rate
and the data format used.
Hence, in the case of a data format of 8 data bits, no parity bit, and one stop bit, the transmission time is
calculated as follows:
Character transmission time [ms] = 1000 * 10 bits / Baud rate
And with the other data formats:
Character transmission time [ms] = 1000 * 11 bits / Baud rate
Process
Data inquiry from the master
Transmission time = n characters * 1000 * x bits / Baud rate
Identification code for end of data inquiry
3.5 characters * 1000 * x bits / Baud rate
Handling of data inquiry by the slave
Reply from the slave
Transmission time = n characters * 1000 * x bits / Baud rate
Identification code for end of reply
3.5 characters * 1000 * x bits / Baud rate
Example
Identification code for end of data inquiry or response in case of a data format 11 /
10 bits.
Waiting time = 3.5 characters * 1000 * x bits / Baud rate
Baud rate
[Baud]
Data format
[bit]
Waiting time
[ms]
9600 11 4.01
10 3.645