FD67 Profibus-DP Manual
91
Token
The active user (master) in possession of the token can carry out data
exchange with the slaves which it has parameterized and configured. On
completion of the data cycle, the active user passes the token to the next
active user.
9.2 FD67
specific
Sensor short-circuit
Short-circuit or overload at Pin 1 of the M12 socket causes the self-
resetting fuse to blow. Each M12 socket is separately fused. A red LED
indicates the fault at the associated M12 socket. This fault is indicated via
the DP diagnosis. The sensor supply restarts automatically after the fault
is cleared. Please not the specific characteristics of analogue A/O
modules.
Actuator cut-off
Short-circuit or overload at an output causes the output to be disabled.
This fault is indicated to the DP master via the DP diagnosis. A red LED
indicates the fault at the associated M12 socket. The output is not
automatically re-enabled. The output or the actuator supply voltage must
be disabled after eliminating the cause of the fault. This clears the short
circuit memory.
Actuator warning
When an output is disabled, the presence of 24V at the associated Pin of
the M12 socket is detected. This is an indication of a "short-circuit" to
+24. A probable cause of this diagnosis is a faulty connection, i.e. a
sensor was connected to a channel parameterized as an output. A red
LED indicates the fault at the associated M12 socket. This fault is
indicated to the DP master via the DP diagnosis. This fault does not
affect activation of the output. It is not possible to detect an actuator
warning when the output is enabled.
Undervoltage
The voltages of the sensor supply and actuator supply are metered
separately. When the voltage drops below 18 V DC, a fault is indicated to
the DP master via the DP diagnosis. When sensor supply undervoltage is
detected, the LED labeled "U
S
" is lit red. When actuator supply
undervoltage is detected, the LED labeled "U
A
" is lit red. This diagnosis
can be masked out via the parameterization.
No voltage
This diagnosis is indicated to the DP master when the supply voltage
drops below 12 V DC. This diagnosis can be masked out via the
parameterization.
External fault
This diagnosis can only be generated by an input parameterized as a
diagnostic input. External fault is indicated when 0 V is present at this
input. Sensors/actuators which meet the DESINA specification are
supported. Alternately, the line can be monitored for open circuit by using
a diagnosis adapter.