In this topology, the BMENOS0300 network option switch is used in place of a BMENOC0301/11 to reduce cost. The BMENOS0300 network option switch is located in an . Its ports are used as follows:
-
The two network ports are configured for a DIO Ring.
-
The service port is configured as an Access port, and supports an engineering tool (for example, Control Expert) resident on a PC.
NOTE: Instead of a PC, a DIO cloud could be connected to the service port.
1
Primary Hot Standby PAC
2
Standby Hot Standby PAC
3
Hot Standby communication link
4
Ethernet RIO main ring
5
(e)X80 RIO drop
6
Ethernet DIO ring
7
Distributed equipment
8
daisy chain
9
Engineering tool resident on PC
NOTE:
-
To achieve acceptable recovery times for the DIO ring, limit its design to a single DIO main ring without sub-rings.
-
RSTP limits the size of the DIO ring to a maximum of 40 switched devices, including the BMENOS0300 module.
-
When you set the BMENOS0300 network rotary switch to
DIO Ring, configure a distributed equipment Ethernet device to be the RSTP root bridge. Refer to the topic
Device Rotary Switch Positions for information about the effects of selecting
DIO Ring.
