Correct the output value
Short-circuit to ground 1H Overload at output Eliminate overload
Short-circuit of output QV to MANA Eliminate the short-circuitA diagnostics alarm is output for each diagnostics event and the ERROR LED flashes on the
digital on-board I/O. You can read out the diagnostics alarms, for example, in the diagnostics
buffer of the CPU. You can evaluate the error codes with the user program.
Table 6- 12 Diagnostics alarms, their meaning and corrective measures
Diagnostics alarm Error code Meaning Corrective measures
Load voltage missing 11H No supply voltage L+ Feed supply voltage L+
Hardware interrupt
lost
16H The digital on-board I/O cannot trigger an
interrupt because the previous interrupt
was not acknowledged; possibly a configuration
error
• Change the interrupt processing in the
CPU and reconfigure the digital onboard
I/O.Meaning Corrective measures
Illegal A/B signal
ratio
500H • Time sequence of the A and B signals
of the incremental encoder do not
meet certain requirements.
• Possible causes:
– Signal frequency too high
– Encoder is defective
– Process wiring is incorrect
• Correct the process wiring
• Check the encoder/sensor
• Check the parameter assignmenThe compact CPU can generate a hardware interrupt for the following events:
● Rising edge
● Falling edge
You will find detailed information on the event in the hardware interrupt organization block
with the "RALRM" (read additional interrupt information) instruction and in the STEP 7 online
help.
The start information of the organization block includes information on which channel
triggered the hardware interrupt. The figure below shows the assignment to the bits of
double word 8 in local data.User Structure Identifier)
W#16#0001 Additional interrupt information of the hardware
interrupts of the digital on-board I/O
2
The channel that triggered the hardware interrupt follows.
Channel B#16#00 to B#16#0F Number of the event-triggering channel (channel
0 to channel 15)
1
The error event that triggered the hardware interrupt follows.
Event B#16#01 Rising edge 1
B#16#02 Falling edgeWhen the internal gate is opened, the technology function
triggers a hardware interrupt in the CPU.
Closing of the internal gate (gate stop) 2 When the internal gate is closed, the technology functions
trigger a hardware interrupt in the CPU.
Overflow (high counting limit violated) 3 When the count value exceeds the high counting limit, the
technology function triggers a hardware interrupt in the
CPU.
Underflow (low counting limit violated) 4 When the count value falls below the low counting limit, the
technology function triggers a hardware interrupt in the
CPU.
Comparison event for DQ0 occurred 5 When a comparison event for DQ0 occurs due to the selected
comparison condition, the technology function triggers
a hardware interrupt in the CPU.
When the change of the count value for an incremental or
pulse encoder was not caused by a count pulse, the technology
function does not trigger a hardware interrupt.
Comparison event for DQ1 occurred 6 When a comparison event for DQ1 occurs due to the selected