System information

FCD 901 48
Issue R2A, 07.2009
XMP1 Release 5.5 System Description
Multipolling
Page 2-40 Proprietary Information Aastra
Setting up a connection between the multipolling master and a
subscriber
1. If the polling master wishes to communicate with a sub-station, it
transmits a "request to send" in the 64 kbit/s data stream of the
multipolling section.
2. All subscribers monitor these data.
3. The subscriber addressed by the multipolling master identifies the
request to send and sets up a connection to the latter.
4. The multipolling master identifies the connection to the required
subscriber.
5. The master station and subscriber are connected to each other.
6. The multipolling section is then occupied and blocked for all other
subscribers.
7. The subscriber addressed can now transmit his data to the multipolling
master.
In the following example, a total of six converters are involved in
multipolling.
The end of the multipolling link is located in node 3, the master station in
node 1. The master station is converter 11/1 in node 1.
Figure 2.21: Multipolling configuration
Node 2 Node 3
Port 1 Port 2
11/2/5 5/1/10
2/2/10
Converter 11/1 is the
multipolling master
Node 1
Port a
14/3/5
11/1 10/3 10/4 10/5
Port 1
12/4 12/5