UMAX0608XX‐1000. Tri‐Axial J1939 CAN Inclinometer. Version 9B
Page: 19-66
2.4.3 Slew Rate Control
The inclinometer has an ability to adjust the CAN transceiver slew rate for better performance
on the CAN physical network, see
J1939 Network
function block for further details.
2.4.4 Network Bus Terminating Resistors
The majority of inclinometers do not have an embedded 120 Ohm CAN bus terminating
resistor. Check the
Technical Specifications
section for the particular part number.
If not internally installed, the 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.
2.5 Default
Settings
The inclinometer is shipped with the following pre-configured settings to transmit angular data
on the CAN bus.
2.5.1 CAN Interface
By default, the inclinometer angular data is transmitted in a standard PGN:
PGN 61481, Slope Sensor Information 2, SSI2
1
.
The inclinometer is also pre-configured the way that it can send data in:
PGN 61459, Slope Sensor Information, SSI;
PGN 65256, Vehicle Direction/Speed, VDS;
PGN 64905, Vehicle Direction/Speed 2, VDS2
.
The user should use EA to activate sending the appropriate preconfigured PGNs by changing
the
Transmission Enable
configuration parameter from
No
to
Yes
, see
CAN Output Message
function block
.
Any other user-defined PGNs can be configured by EA as well.
1
In firmware V1.xx, AX060800, AX060806, AX060807 transmit angular data in SSI PGN by default.
2.5.1.1 PGN 61459, Slope Sensor Information, SSI
This PGN provides measurements of the vehicle pitch and roll angles and a measurement of
the vehicle pitch rate. It has the following parameters:
Transmission Repetition Rate:
10 ms
Data Length:
8
Default Priority:
3
Parameter Group Number:
61459
Start Position
Length
Parameter Name
SPN
1-2
2 bytes
Pitch Angle
3318