Communication / USS
02.2004
6SE7087-6QX70 (Version AD) Siemens AG
8.1-4
Compendium Motion Control
SIMOVERT MASTERDRIVES
In the address byte, information other than the node number is coded:
The individual bits in the address byte are assigned as follows:
= 0: No mirror telegram
Bit No.
7
6
5
4
3
2
1
0
STX
LGE
ADR
1.
2.
n
BCC
Net characters
Slave nodes No. 0 to 31
= 1: Mirror telegram
= 1: Special telegram (for an explanation, see below)
= 0: Standard; bits 0 to 6 are valid and must be evaluated
= 0: No broadcast
= 1: Broadcast, address bits (No. 0 to 4) are not evaluated
Fig. 8.1-3
Assignment of the address byte (ADR)
The master ensures cyclical telegram data transfer. The master
addresses all of the slave nodes one after the other with a task
telegram. The addressed nodes respond with a reply telegram. In
accordance with the master-slave procedure, the slave, after receiving
the task telegram, must send the reply telegram to the master before
the master can address the next slave node.
The sequence of the addressed slave nodes can be specified, for
example, by entering the node numbers (ADR) in a circulating list
(polling list) in the master. If it is necessary to address several slaves in
a faster cycle than the other slaves, their node number can occur
several times in the circulating list. A point-to-point link can be
implemented by means of the circulating list, in which case only one
node is entered into the circulating list.
Assigning the
address byte (ADR)
Data transfer
procedure
Handling data
transfer