&RPPXQLFDWLRQZLWK0,&520$67(5YLD352),%86'3 (GLWLRQ$
PROFIBUS Optional Board Operating instructions
30 6SE6400-5AK00-0BP0
5XOHVIRUSURFHVVLQJUHTXHVWVUHVSRQVHV
½ A request or a response can only ever refer to one parameter.
½ The master must repeat a request continuously until it has received the
appropriate response.
½ The master detects the response to a request it has sent by
♦ evaluating the response identifier,
♦ evaluating the parameter number PNU,
♦ evaluating the parameter index IND if necessary, or
♦ evaluating the parameter value PWE if necessary.
½ The complete request must be sent in one telegram. Request telegrams
cannot be split. The same applies to responses.
½ In the case of response telegrams which contain parameter values, the drive
always returns the momentary parameter value when repeating response
telegrams.
½ If no information needs to be fetched from the PKW interface in cyclical
operation (only PZD data are relevant), then the "No request" request telegram
must be issued.