BONFIGLIOLI Vectron Agile Series, Communications Manual

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Profibus DP V1 Agile 29 06/2010
Handling of the Objects
16.1.5 Sequence of Communication
A request from the master is always answered with a reply from the slave. Each PPO can only accept
one request or one reply at a time. In this way, a defined hand-shake procedure between master and
slave must be complied with.
In the initial situation, the request and reply identification must = 0. The master sets its request
identification and waits for the slave to change the reply identification from 0 to ≠ 0. Now, the reply
from the slave is available and can be evaluated. Thereupon, the master sets its request identification
= 0 and waits for the slave to change the reply identification from ≠ 0 to 0. With this, the
communication cycle is completed and a new one can start.
Attention! The slave only replies to new requests if it has reacted to the request identification = 0
with the reply identification = 0.
Handling of the Objects
16.1.6 Communication Examples
Parameter Setting
No. Description Type Write /
Read
Format Min. Max. Fact. Sett.
400 Switching frequency P-W S/L x 1 8 2
480 Fixed frequency 1 P[I]-D S/L xxxx.xx Hz -999.00 999.00 5.00
Example 1:
Parameter 400 is one word (P-W), int, not data set switch-over capable and is to be read.
Request from Master:
AK = 1 (Request Identification = read parameter value
PNU = 400 (= 0x190)
IND = 0
PWEh = 0
PWEl = 0
PKW area
Designation PKE IND PWE high PWE low
Content Parameter
Identification
Index Parameter value
High Word
Parameter value
Low Word
High
Byte
Low
Byte
High
Byte
Low
Byte
High
Byte
Low
Byte
High
Byte
Low
Byte
0x11 0x90 0 0 0 0 0 0
Byte No. 0 1 2 3 4 5 6 7
Reply from Slave:
AK = 1 (reply identification = transmit parameter value int/uint)
PNU = 400 (= 0x190)
IND = 0
PWEh = 0
PWEl = value
PKW area
Designation PKE IND PWE high PWE low
Content Parameter
Identification
Index Parameter value
High Word
Parameter value
Low Word
High
Byte
Low
Byte
High
Byte
Low
Byte
High
Byte
Low
Byte
High
Byte
Low
Byte
0x11 0x90 0 0 0 0 0 value
Byte No. 0 1 2 3 4 5 6 7