Operating instructions

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4.8.3 Emergency message, reaction
If a slave on the system bus suffers a fault, it transmits the emer
g
ency tele
g
ram. The
emer
g
ency tele
g
ram marks the node ID for the identification of the failed node via its
identifier and the existing fault message via its data contents (8 bytes).
After a fault has been acknowledged on the slave, the latter again transmits an emer-
gency telegram with the data content zero.
The emergency telegram has the identifier 128 + node ID ( = 129 ... 191)
The system bus master evaluates the emergency telegrams of the slaves. Its reaction
to an emergency telegram can be set with
Emergency Reaction 989.
Operation mode Function
0 -Error The system bus master receives the emergency
telegram and switches-off
1 -No Error The Emergency Telegram is displayed as a warn-
ing
Operation mode - parameter 989 = 0 – Error
Behavior of the system bus master in
Emergency Reaction 989 = 0 / Error:
As soon as the system bus master receives an emer
g
ency tele
g
ram, it also switches to
failure mode and reports the failed subscriber on the basis of its ID via the kind o
f
error. Only the subscriber is reported, not the cause of the error.
The fault message on the system bus master via
Current error 260 is 21nn with nn
= node ID (hexadecimal) of the slave in which a fault switch-off exists.
In addition, the system bus master reports the warning Sysbus (0x2000) via the pa-
rameter
Warnings 270 Bit 13.
If a fault switch-off occurs on a number of slaves, the first slave to transmit its emer-
gency telegram is displayed on the system bus master.
Operation mode - parameter 989 = 1 – No Error
Behavior of system bus master in the case of
Emergency Reaction 989 = 1 / No Er-
ror:
As soon as the system bus master receives an emer
g
ency tele
g
ram, it reports the
warning Sysbus (0x2000) via the parameter
Warnings 270 Bit 13.
Note: In both cases, the Boolean variable SysbusEmer
g
ency with source number
730 is set to TRUE in the system bus master. It can be used in the system
bus master and (in transmission via a TxPDO) in the slaves for a defined
shutdown.
SysbusEmergency is also set if the system bus master breaks down.
Resetting of SysbusEmergency is done with the fault acknowledgment.