Data query sequence
Time sequence | The time sequence of a data query looks as follows: |
Master
Data query
Data query
Slave
Reply
7865z12e/1102
t0
t1
t0
t2
t0 Identification of end = 3 characters (time is dependent on the Baud rate)
t1 This time is dependent on internal handling. The maximum handling time is 250 ms
t2 This is the time required by the device to switch from the transmitting mode back to the receiving mode.
This time must be observed by the master before it makes a new data query. It must always be maintained, even if the new data query is sent to some other device.
t2 20 ms
Communication during the slave’s internal handling time
The master is not allowed to make any data queries during the slave’s internal handling time.
Data queries made during that period of time will be ignored by the slave.
Communication during the slave’s response time
The master is not allowed to make any data queries during the slave’s response time. Data queries made during that period of time cause all data currently on the bus to become obsolete.
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Siemens Building Technologies | CC1A7865.1en |
HVAC Products | 31.10.2002 |