Siemens LMV5 Quick Start Manual page 197

Data query process
Time diagram
Communication during the slave's internal handling time
Communication during the slave's reply time
Number of messages
LMV5 QSG Rev 4
A data query is made according to the following time diagram:
Master
Data query
Slave
t
0
7550z08e/0703
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 de-
pendent on the data type (internal and external data) and on the number of data;
for more detailed information, see below!
t2  20 ms
t2
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
During the slave's internal handling time, the master is not allowed to make any data que-
ries. The slave ignores data queries made during this period of 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 de-
leted.
The number of addresses per message are limited:

20 addresses of the size of one word when reading

6 addresses of the size of one word when writing
Sec 8 Pg 3
Reply
t t t
1 0 2
Data query
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