ElmoMC SimplIQ Software Manual - Manual (Page 206)

SimplIQ Software Manual Limits, Protections, Faults and Diagnosis
MAN-SIMSW (Ver. 1.4)
13-11
Before enabling the motor, the drive tests all parameters to ensure that they are sensible.
For example, the variables CA[4], CA[5] and CA[6] define how the Hall sensors are
ordered. If CA[4] equals CA[5], two Hall sensors are assigned to the same position, which
is illogical. If CA[4] = CA[5], the command MO=1 will fail and will return the error code
54 to indicate a bad database. In order to determine the reason for this type of failure, use
the CD command, which will return:
Null address=0
Failure address=0
Called Handler=none
Database status:
CA[4], error code=37
The first lines establish that the CPU did not detect an exception (refer to following
section). The last line states that parameter CA[4] yielded the error code 37, meaning that
two Hall sensors are defined for the same place.
13.9.3 Device Failures and CPU Dump
Programming bugs or errors may lead to CPU exceptions, such as an attempt to divide
by zero or to access a variable that does not exist. Programming errors may also lead to
CPU overloading, in which case the CPU is not able to complete its control tasks on time
and thereby causes the CPU stack to overflow.
For this reason, SimplIQ drives use traps for CPU exceptions and stack overflow. When it
traps an exception, it:
ƒ
Shuts off all controller activity and aborts any motion to freewheeling
ƒ Writes down the exact trap that was activated, along with the address in the firmware
that caused the exception
After the exception, the communication remains enabled so that the drive can be queried
about the event. The motor, however, cannot be set to work again until the drive is
rebooted.
A CPU exception is detected using the CD and SR commands. The SR command indicates
only that an exception occurred, while the CD (CPU dump) command provides the
details. The CD command provides the report as follows:
Null Address Code Address in Firmware in which Exception Occurred (0 if OK)
Failure
address Code address in firmware when stack overflow has been detected (0 if
OK)
Called handler A string describing the type of exception:
ƒ A divide-by-zero attempt
ƒ An attempt to access a non-existing variable
ƒ Many other possible exceptions
This string is “none” if no exception was trapped.
Table 13-2: CD Reported Elements
The CPU dump also returns the database status, as described previously.