ABB AC 800M, User Manual

Page: 45 / 118

Section 2 Transmission Technology Monitoring of the communication quality
3BDS009029R5001 B 45
Monitoring of the communication quality
Optical link modules mostly provide segment monitoring at the RS485 and fibre
optic port.
If the operating mode ”Electric port with segment monitoring“ is set at the RS485
port, each receiver monitors the RS485 bus segment connected to it for faulty
frames or continuously busy networks. If faulty frames are received by the receiver,
or if the network is busy for longer than the maximum permitted send time,
forwarding of the received signals is blocked until frames can be received again
correctly, or if no signal is received for one second.
Line monitoring with echoes
The optical link modules enable the connected optical paths to be actively
monitored for interruptions in the fiber line by means of the functions ”Send echo“,
”Monitor echo“ and ”Suppress echo“.
Figure 9. Optical link module with 1 RS485 port and redundant fibre optic ports
The following description of monitoring functionality can be build up with the
optical link modules from Hirschmann and Phoenix Contact. Optical link
modules from other manufacturer does not always support this functionality.
One RS485 port
Redundant fibre optic port
Power supply