Version 2.0.3 Preliminary Documentation – May be Subject to Change 17-36
3.2. Diagnostic
Log
In order to support requests for DM2, the controller stores diagnostic data in a non-volatile log.
There are two diagnostic log entries associated with each input channel. Each entry is a record of
the SPN, FMI and OC for any fault that has occurred.
If the “Generate Diagnostic Messages” setpoint for the I/O channel is set to false, the OC for any
DTCs for that channel will NOT be updated in the log, even if the controller detects the associated
fault.
As soon as the controller detects a new (previously inactive) fault, it will start decrementing the
delay timer for that channel. If the fault has remained present during the delay time, then the
controller will set the DTC to active, and will increment the OC in the log. A DM1 will immediately
be generated that includes the new DTC. While there are any active DTCs, a DM1 will be sent
every second, as per the standard.
If the controller receives a request for a “Diagnostic Data Clear/Reset for Previously Active DTCs”
(DM3) it will clear the OC of ALL the inactive DTCs in the log. The OC for active diagnostics is not
changed.
If the user changes either the “SPN” or the “Diagnostic Lamp Type” setpoints, the diagnostic
entries for that channel are updated, and the OC is set to zero.
3.3.
Clearing Active DTCs
The “Diagnostic Lamp Type” setpoint will not only determine what lamp is set in a DM1 or DM2, but
also how active diagnostics will be cleared.
For input channels that set the
Protect Lamp
or
Amber Warning Lamp
when detecting a fault, if the
fault goes away, then the controller automatically makes the SPN/FMI combination previously
active, and will no longer include it in the DM1.
For an input error to be considered to have been cleared, the input must have either gone above
the minimum error, or dropped below the maximum error, by the amount shown in the table below.
Voltage Current PWM Frequency
250 mV
250 uA
1.0%
10 Hz/RPM
However, for channels that set the
Red Stop Lamp
, DTCs are NOT automatically made inactive
once the fault clears. Instead, they can only be cleared upon request for a “Diagnostic Data
Clear/Reset for Active DTCs” (DM11).
Upon receiving a request for a DM11, the controller will check the status of all the active DTCs that
set the
Red Stop Lamp
. If the fault is still present, then the DTC remains active. Otherwise, the
DTC is made previously active, and it is no longer included in the DM1.
If any one of the
Red Stop Lamp
channels still has an active fault when the request for the DM11 is
received, the controller will respond with a NAK, indicating that it was not able to complete the
request. If, however, all the DTCs have now been made previously active, it will respond with an
ACK. If all the faults in the module are cleared at this point, i.e. all DTCs are now inactive, the
controller will send a DM1 message indicating that there are no longer any active DTCs.
