Installation guide

Estimating Network Performance

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NETWORK

BP85 BRIDGE PLUS

Figure 42 Bridge Communication Paths

The bridge contains eight independent Data Master paths and eight

independent Data Slave paths for each of its two network ports.

Messages received at the network A port with destinations on network

B or beyond are given Data Slave paths on network A, and then passed

to Data Master paths at the network B port. In the other direction,

incoming messages at network B are given Data Slave paths at that

port and Data Master paths at network A.

As each message is allocated one slave path and one master path in the

bridge, up to eight messages can be routed from each network to the

other without queueing.

When all eight paths are in use in a given direction, other incoming

messages will queue in the bridge, unless they have previously been

routed through another bridge. Messages that have already been

passed through a bridge will cause an error response when they are

received at the second bridge. The error response will be returned to

the error status register of the originating MSTR function, and can be

tested by the application program. This prevents tieing up paths in the

originating device due to excessive queueing. MSTRs can be

temporarily released (using their ABORT inputs), and their Data

Master paths given to other MSTRs.