AXIOMATIC AX180800, User Manual

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UMAX180800, 20 Thermocouple, 2 RTD, 4 Inputs, 6 Relays Dual CAN Controller Version 1 Page: 11-71
FMI=4, Voltage Below Normal, Or
Shorted To Low Source FMI=3, Voltage Above Normal, Or Shorted To
High Source
FMI=5, Current Below Normal Or Open
Circuit FMI=6, Current Above Normal Or Grounded
Circuit
FMI=17, Data Valid But Below Normal
Operating Range
– Least Severe Level
FMI=15, Data Valid But Above Normal
Operating Range
– Least Severe Level
FMI=18, Data Valid But Below Normal
Operating Range
– Moderately Severe
Level
FMI=16, Data Valid But Above Normal
Operating Range
– Moderately Severe Level
FMI=21, Data Drifted Low FMI=20, Data Drifted High
If the FMI used is anything other than one of those in Table 30, then both the low
and the high faults will be assigned the same FMI. This condition should be
avoided, as the log will still use different OC for the two types of faults, even though
they will be reported the same in the DTC.
When the fault is linked to a DTC, a non-volatile log of the occurrence count (OC) is kept. As
soon as the controller detects a new (previously inactive) fault, it will start decrementing the
Delay Before Sending DM1 timer for the Diagnostic function block. If the fault has remained
present during the delay time, then the controller will set the DTC to active, and it will
increment the OC in the log. A DM1 will immediately be generated that includes the new DTC.
The timer is provided so that intermittent faults do not overwhelm the network as the fault
comes and goes, since a DM1 message would be sent every time the fault shows up or goes
away.
J1939 Network function block for further details.
2.5.1 Network Bus Terminating Resistors
The controller does not have an embedded 120 Ohm CAN bus terminating resistor.
Terminating resistors should be installed externally on both ends of the CAN twisted pair cable
according to the J1939/11(15) standards to avoid communication errors.
Even if the length of the CAN network is short and the signal reflection from both ends of the
cable can be ignored, at least one 120 Ohm resistor is required for the majority of CAN
transceivers to operate properly.
2.6 Modbus TCP Interface
The Modbus TCP/IP interface
1
runs over a standard 10/100 Mbit/s Ethernet link. The controller
is presented as a slave device (a server) on the Modbus network. It supports with up to 8
simultaneous client connections from master devices.
1
The interface is compliant with: