MC33810 Fault Detail Definition
This MotoHawk™ block allows the detailed fault information for an MC33810 output channel to be recovered as an enumeration.
Block ID
MC33810 Fault Detail
Library
MotoHawk_lib/Diagnostics
Description
Overview
This MotoHawk™ block allows the detailed fault information for an MC33810 output channel to be recovered as an enumeration. It assumes an IO Fault Status block will be used to query the general fault status of the resource and that this block is only used to determine specifics about a fault. Requesting detailed fault information without an IO Fault Status block existing in the model could lead to an invalid response.
This block reports the last observed fault detail. A channel that is no longer in fault will continue to report the last observed fault detail. Thus this block does not replace the IO Fault Status block, which is able to detect whether a channel is currently in fault.
Only resources that utilize the MC33810 support this capability. No resources support this fault detail if the block has an empty resource list.
Some of the faults detected by the MC33810 are specific to SPK outputs. The MC33810 hardware further assumes that these outputs will be connected to spark coils and driven in a manner that implies spark control. As such there is an expectation that no two SPK channels will turn off at the same time and that the amount of overlap is deterministic. Driving an asynchronous PWM on one of the SPK channels does not fit this expected behavior. The driver will allow this to occur, but its diagnosis may be compromised as a result. For instance the MC33810 uses a nominal current diagnostic to determine whether a coil has suffered an open primary condition. This nominal current diagnostic is shared by all of the SPK channels on a device (and in some cases by multiple devices) and so it will be compromised if an asychronous PWM were to be used on one of the SPK channels.
Signals
Fault Detail (uint8, enum)
The faults as detailed by the MC33810 data sheet are enumerated. In some cases there are similar faults, but with different enumerated values. The faults correspond to the detail detectable by the MC33810, which is different depending upon the capability of the channel. The most severe condition is presented if the MC33810 is able to detect multiple faults.
"motohawk_mc33810_faultdetail_enum" is a script that returns a cell array with the enumeration. It can be used in the Enumeration field of a probe to decode the return value of this block.
No Faults Observed (value=0)
No faults have been observed on the channel
Open Detected While Asserted (value=1)
OUT type channels on the MC33810 are able to detect open faults while asserted (ON) by monitoring load current. A false report can result if the load current is not sufficient to make this diagnostic reliable. Use the Open while asserted block to configure whether this diagnostic is enabled on the MC33810.
Open Detected While Not Asserted (value=2)
OUT type channels on the MC33810 are able to detect open faults while the load is not asserted (OFF) by monitoring drain voltage. A false report may result if the load has been connected to a main power relay that is currently not pulled in as that represents an open circuit
Short to Battery (value=3)
OUT type channels on the MC33810 are able to detect a short to battery condition
Temperature Limit Shutdown (value=4)
OUT type channels on the MC33810 have a temperature limit shutdown. This fault is reported in preference to the short to battery when the MC33810 presents both fault conditions to MotoHawk™.
Open Detected (value=5)
Spark channels on the MC33810 that are configured for general purpose operation (because they have a MOSFET driver) are able to detect open load faults. The mechanism is different to that used when the spark channel has an IGBT type driver. Software automatically configures a channel to operate as a MOSFET or IGBT based upon the hardware configuration.
Short Detected (value=6)
Spark channels on the MC33810 that are configured for general purpose operation (because they have a MOSFET driver) are able to detect short circuit faults. The mechanism is different to that used when the spark channel has an IGBT type driver. Short detection attributes can be configured via the MC33810 GPGD Fault Configuration block.
Open Secondary (value=7)
Spark channels on the MC33810 that are configured to operate with spark coils are able to detect an open secondary condition. Use the Spark Control Definition block to configure the detection of this fault.
Max Dwell (value=8)
Indicates that the channel was shutdown because of an over dwell situation. This feature is only enabled on modules that do not support micro level dual stop control on their PSP event. MPC5xxx based cores won't utilize this feature.
MAXI Current Observed (value=9)
The maximum current as defined by the MC33810 DAC Settings block was observed while the channel was asserted.
Open Primary (value=10)
The nominal current as defined by the MC33810 DAC Settings block was not observed when the channel was asserted. This fault won't be detected unless it is enabled via the MC33810 Spark Fault Definition block.
The output must be using a compatible behavior like PSP or Oneshot for this diagnostic to operate. These behaviors are considered compatible because they imply control of the outputs in a manner where they won't overlap and will thus emulate spark coil like control. PSP (Periodic Synchronized Pulse) is the underlying behavior used by MotoHawk to generate the crank synchronous pulses required by ignition control (via blocks like the Dual PSP or the Spark Sequence block).
Open circuit detection won't function if the output is used with a Discrete Output or PWM Output behavior.
Block Parameters
| Parameter Field | Values | Comments/Description |
|---|---|---|
| Name (Optional) | Alpha-numeric text, single-quote enclosed | An optional name. When used the name must be C-legal. Therefore is must have no special characters such as spaces, dashes or commas (underscore allowed). It must also be unique. |
| Resource | Drop-down list | Module resource for this block (target module dependent). |