Operating Instructions | symphony 5.3 A – 06/2009
5
Start-up
5
Start-up
31
Faulty response from control unit:
If a returned response is incomplete or faulty, the CPU responds with an
NAK (15
H
, only 1 byte, without frame). Otherwise, the command code (with
pertaining length information) is regarded as a response and the data that
may be required is transmitted.
Particularities during data communication:
Data request and response
For the data communication between PC and microcontroller, the following
particularities must be observed:
The microprocessor stores an int or unsigned int value with the sequence
<Highbyte>, <Lowbyte> in the memory. For the PC, this sequence is
reversed. The microcontroller transmits these values in its format, i.e. the
PC must reverse the sequence of the bytes. For floats, there is no diffe-
rence.
Example: Temperature data request and response