PC104 View Datasheet(PDF) - PMD
Part Name
Description
MFG CO.
'PC104' PDF : 70 Pages View PDF
2
Operation
2.3.8 Reset Monitor
In addition to resets which are explictly requested by the user (detailed in the previous section), some
reset conditions can occur automatically. During normal operations the motion processor is only reset
during power-up. A reset serves the purpose of initializing values and bringing the motion processor to
a known and consistent state. On occasion though, the motion processor will be reset due to one of a
few anomalous conditions.
ReadIO and WriteIO commands
To determine the source of a card reset special instructions to read the reset source have been provided.
The command ReadIO with an address of +2 should be used. The following table shows the encoding
of this I/O address word:
Address
2
Bit
location
0-11
12
13
14
15
Signals
Reserved
Software command: a 1 value in this bit indicates
reset caused by a software command by the user.
Under voltage detection: a 1 value in this bit
indicates reset caused by under voltage detection.
External signal: a 1 value in this bit indicates
reset caused by external signal. Such a reset
originates from the J1 and J7 connectors on the
connector ‘Reset’. When this signal is brought low,
a reset condition occurs.
Watch dog timeout: a 1 value in this bit indicates
reset caused by watch dog timeout.
Once a reset condition has occurred, the reset status stored in location +2 described above can be
cleared by a WriteIO command to address +2 with a value of 0.
Example
To determine that a reset has occurred, and to determine what the reset condition is, the C-Motion
command PMDReadIO(axis_handle, 2, &reset_value) is used. Assuming that a watchdog timer event has
occurred, the value returned would be 0x8000. To reset the reset monitor word, the command
PMDWriteIO(axis_handle, 2.0) is sent.
C-Motion commands
In addition to accessing these signals using the C-Motion commands PMDReadIO and PMDWriteIO,
you can use card-specific C-Motion functions for this purpose. The available card specific functions for
this feature are:
C-Motion
command
PMDMBGetResetCause
Arguments
axis_handle,
reset_cause
Function description
This function returns the reset cause in the variable
reset_cause and also clears the reset condition.
Connections & associated signals
The reset monitor is an internal function of the card. Thus there are no signals directly associated
with this function.
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Navigator-PC/104 User’s Guide
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