Phoenix Contact 2861205, Руководство пользователя

Страница: 57 / 88

Commissioning and functional test
5981_en_06 PHOENIX CONTACT
57
8.3 Operation
If all the green LEDs on the field multiplexer and the I/O terminals light up, the field
multiplexer station is operating, and data transmission is active.
The following activities take place during normal operation:
– Exchange process data on the local buses, and between a station and its opposite
station over the remote bus
– Display of I/O errors
– Monitoring of the field multiplexer timeout
Controlling the alarm relay If data transmission is not possible within a predefined period (timeout), the alarm relay is
activated (see also “Flowchart” on page 62). Both field multiplexer stations enter the stop
state, and a reset is generated at both stations.
The field multiplexer system automatically tries to start up again after a timeout or after a
reset. If no error is found when restarting (remote bus and local bus operating correctly and
correctly configured for each other), data transmission is resumed automatically. If an error
is found, the field multiplexers will continue to attempt to restart the system.
ACHTUNG: Malfunction
Changes to a local bus configuration during operation are not permitted under any
circumstances . Always switch off power first before you make any changes to the field
multiplexer system.
Only the digital outputs are reset. The analog terminal outputs remain unchanged
(maintain their last value), while the stations are stopped.
The alarm relays at the two field multiplexer stations are not always triggered at the same
time, as error detection occurs at each station independently of the remote station. For
instance, if the power to one field multiplexer station fails, the alarm relay is triggered at the
affected station immediately, but it may take up to 1 s before the opposite station triggers.
If one station stops, the second station will always change to stop state as well.