Advanced Error-Handling - Control Techniques UD70 User Manual

9.4

Advanced error-handling

Errors that occur when the program is running are usually due to
programming errors, but can sometimes occur due to external influences.
For example, an error signifying a serial communications loss could occur if
incoming data from an I/O Box is lost due to the cable being broken.
Normally, the
If this is undesirable, the
as follows:
All Tasks are stopped.
1
The Drive is tripped (if the trip is enabled). See the Trip enable
2
parameters in UD70 setup parameters in Chapter 10 Parameters.
The number of the error is placed in parameter #88.01 of the
3
The
4
ERROR
determine the cause of the run-time error and take necessary action,
such as stopping the Drive system in a controlled manner.
All standard DPL instructions can be used in the
The cause of the error can be determined by reading the virtual parameter
#88.01. This gives the appropriate error code defined in Run-time Trip
Codes earlier in this chapter.
When the Global run-time trip enable
Drive is not automatically tripped. If the Drive is required to be tripped,
write the error code to the appropriate trip code parameter (shown in Trip
codes earlier in this chapter).
To reset the
1070.
Remember that no other DPL tasks will be running after a run-time error has
occurred.
See the on-line help for an example of the
UD70
Issue code: 70nu2
halts all Tasks, and optionally trips the Drive.
UD70
Task can be used. The sequence of events is
ERROR
task is executed. The instructions in the
Global run-time trip enable parameter (#17.14) is not set at 1, the
and restart the DPL program, set parameter #88.01 at
UD70
UD70
Task can
ERROR
Task.
ERROR
task.
ERROR
Diagnostics 9-5