WAGO 750-643 Manual page 28

28 • 750-643 [MP-Bus Master Module]
Network structure
If an external master is detected by the module, the MP-Bus module switches
off its own master functionality, as long as the external master is active and is
sending telegrams. This condition is signaled to the fieldbus controller by
means of the associated status bit in the extended status byte via the module
bus.
The module also switches off its master functionality when the 24 V supply
voltage is applied to the "Enable Handheld" input.
The system does not exit this state until it detects that the external master is no
longer sending telegrams or the 24 V supply voltage has been removed from
the "Enable Handheld" input. After this change of state, the MP-Bus carries
out an unsolicited initialization of the driver and switches to waiting mode
with the receiver active.
WAGO-I/O-SYSTEM 750
I/O Modules