System Limits; Number Of Profibus Stations; Number Of I/O Modules - ABB S900 Manual

I/O System S900
Communication Interface for PROFIBUS DP, CI920
•
simulate (force) the S900 inputs/outputs
•
configure the connected HART field devices
Selective loading of configuration data and parameter settings while the
system is running allows you to
•
modify specific parameters of the communication interface or of
individual I/O modules
•
add more S900 stations
•
add, remove or replace S900 I/O modules.
All I/O modules whose parameter settings and configuration data are not
changed continue cyclic communication. As long as the master is
downloading data, all S900 outputs hold their states. Examples for modern
master systems meeting the requirements stated above are:
•
ABB AC800F
•
ABB Symphony CMC60-2 / CMC70
•
ABB AC800M

System Limits

Number of PROFIBUS stations

Up to 127 can be addressed within a PROFIBUS network. This number
includes the PROFIBUS – master. Up to 32 stations can be connected to a
PROFIBUS DP segment. When using repeaters, one can separate the network
into several segments. Using the intrinsically safe PROFIBUS - DP, up to 10
stations can be connected to each segment.
The transmission rate and the permissible cable length specified for the
segment must be observed. For example, a cable length of 400 m (1314ft) is
permissible for a network with a transmission rate of 500 kbaud. Longer
cables are possible when using fiber optic cables.

Number of I/O Modules

S900 can handle up to 16 I/O modules. They can be configured via the
PROFIBUS, and their parameters can be defined individually for every
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