Siemens LMV 5 Series, Technical Instructions, Page: 273 / 374

LMV Series Technical Instructions
Document No. LV5-1000
SCC Inc. Page 3 Section 8
Example Marking for data query or end of reply with data format 10 / 9 bits
Waiting time = 3.5 characters * 1000 * x bits / Baud rate
Baud rate [Baud] Data format [bit] Waiting time [ms]
9600 10 3.125
9 2.813
Data query process
Time diagram A data query is made according to the following time diagram:
where:
t0 Marking for end = 3.5 characters (time is dependent on the Baud rate)
t1 This time is dependent on internal handling; the maximum handling time is
dependent on the data type (internal and external data) and on the number
of data; for more detailed information, see below!
t2
t2
≥
20 ms
This time is required by the device to switch from transmitting back to
receiving; this time must be observed by the master before a new data
query is made; it must always be observed, even if a new data query to
some other device is made
Communication during the slave’s internal handling time
During the slave’s internal handling time, the master is not allowed to make any data queries. The slave
ignores data queries made during this period of time.
Communication during the slave’s reply time
During the slave’s reply time, the master is not allowed to make any data queries. Data queries made
during this period of time cause all data on the bus at this instant to be deleted.
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