ABB AC 800M, User Manual

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Section 2 Transmission Technology Basics of fibre optics topology technologies
3BDS009029R5001 B 49
The following ambient conditions must be fulfilled to ensure that network
configuration functions correctly:
• The parameters MIN T
SDR
described in the PROFIBUS standard EN 50170
must be set to a value 11 on all terminals. This is usually the case, but the
setting should be checked if communication malfunctions continuously arise.
• When configuring your network, select low bus subscriber addresses wherever
possible. This ensures that master time-out times which may arise are kept as
short as possible in the event of a malfunction.
Line topology without optical fiber
link monitoring
Use this operating mode if you connect an optical link module with another optical
fiber network component, which does not send a frame echo and does not expect or
is not compatible with a frame echo in accordance with PROFIBUS guidelines
(optical/electrical converter).
Monitoring mechanisms, to be set on the optical link modules:
• Send echo: no
• Monitor echo: no
• Suppress echo: no
• Monitor: no
• Segmentation: no
Individual fiber links are not monitored in this operating.
Refer to the manufacturer’s manual of the optical link modules concerned for details
about how to alter the settings.
Low bus subscriber addresses are not necessary for the bus configuration with
ABB Control IT AC 800M in connection with CI854(A).