UMAX090690. Version: 1.2 Preliminary Documentation
– May Be Subject To Change
19-37
CAN Transmit 1
Default Transmit Data
Byte
Position
Bit
Position
PGN
1
Charger 1 Mode
1
st
1
st
0xFF00
2
Charger 1 Voltage
2
nd
3
rd
0xFF00
3
Charger 1 Current
3
rd
5
th
0xFF00
4
Charger 1 Temperature
4
th
7
th
0xFF00
CAN Transmit 2
Default Transmit Data
Byte
Position
Bit
Position
PGN
1
Charger 2 Mode
1
st
1
st
0xFF01
2
Charger 2 Voltage
2
nd
3
rd
0xFF01
3
Charger 2 Current
3
rd
5
th
0xFF01
4
Charger 2 Temperature
4
th
7
th
0xFF01
Table 4
– Default CAN Transmit Messages
4.6.
CAN Receive Function Block
The CAN Receive function block is designed to take any SPN from the J1939 network and use it
as a control/enable/override source for any relay outputs or CAN Transmits.
The
Receive Message Enabled
is the most important setpoint associated with this function block
and it should be selected first. Changing it will result in other setpoints being enabled/disabled as
appropriate. By default, all receive messages are enabled.
Once a message has been enabled, a Lost Communication fault will be flagged if that message is
not received within the
Receive Message Timeout
period. This will trigger a Lost Communication
event if the cell input associated with the CAN Receive message is set to User Controlled under Rx
Timeout Setting. In order to avoid timeouts on a heavily saturated network, it is recommended to
set the period at least three times longer than the expected update rate. To disable the timeout
feature, simply set this value to zero, in which case the received message will never timeout and
will never trigger a Lost Communication fault.
By default, all control messages are expected to be sent to the battery charger on Proprietary B
PGNs. However, should a PDU1 message be selected, the battery charger can be setup to receive
it from any ECY by setting the
Specific Address that sends the PGN
to the Global Address
(0xFF). If a specific address is selected instead, then any other ECU data on the PGN will be
ignored.
The
Receive Data Size
,
Receive Data Index in Array (LSB)
,
Receive Bit Index in Byte (LSB)
,
Receive Resolution
and
Receive Offset
can all be used to map any SPN supported by the J1939
standard to the output data of the Received function block.
As mentioned earlier, a CAN receive function block can be selected as the source of the control
input for the charger function blocks. When this is the case the
Receive Data Minimum
(Off
Threshold) and
Receive Data Maximum
(On Threshold) setpoints determine the minimum and
maximum values of the control signal. As the names imply, they are also used as the On/Off
thresholds for digital output types. These values are in whatever units the data is AFTER the
resolution and offset is applied to the CAN Receive signal.
