Siemens SIMOVERT MASTERDRIVES Manual page 393

Communication / PROFIBUS
8.2.9.7 Communication interface
Node address
8.2.9.8 Clock synchronous application
Pos Controller
clock time
(T )
MAPC
Master
R1 R2
DP cycle
T S1 S2 S3 MSG
Speed/current
controller clock
time
T
SAPC
R1
Slave 1...3
T = 0
I
8.2-106
P918: Node address
Value range 0 – 125 (126 is reserved for start-up purposes)
The node addresses 0, 1 and 2 are generally occupied by master
and configuration tools and therefore should not be used for
slaves on the PROFIBUS. Address 3 is the first appropriate node
address to be used for a slave on the PROFIBUS.
Course of an isochronous DP cycle
Example (simplest DP cycle, standard case for MASTERDRIVES)
R3 R1 R2
Reserve T S1 S2 S3 MSG
R1 R1 R1 R1 R1
Fig. 8.2-37 Example: simplest DP cycle
In this example four DP cycles are needed for a response in the position
control circuit.
♦ 1. Actual value recording
♦ 2. Actual value transmission (slave -> master)
♦ 3. Position controller
♦ 4. Setpoint transmission
This model makes few demands on the computing output of the master,
but leads to an increase in the control-specific dead time:
Dead time = 4 * T
DP
T = 0
M
R3 R1 R2 R3
Reserve T S1 S2 S3 MSG
R1 R1 R1 R1
(in slave)
(in master)
(master -> slave)
.
6SE7087-6QX70 (Version AG)
Compendium Motion Control
R1 R2 R3
Reserve T S1 S2 S3 MSG
R1 R1 R1 R1 R1
Siemens AG
SIMOVERT MASTERDRIVES
05.2006
Reserve T
R1 R1
T = 0
O