Heinzmann Triton OMD, Manual

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7 General communication functions overview
20 Triton OMD CAN protocol / Rev.-No. 03
On receipt of kSensNumDirectCountCommand , in addition to telegram retransmission, sensor
also responds to the master with
kSensNumReversCountCommand
telegram, with running
sensor counter data item value incremented.
Master can easily calculate the actual number of the sensors using the following logic:
Actual number of sensors in the network is equal to the sum of highest running sensor counter
(reverse counter) values, received by master on CAN1 and CAN2 ports.
The calculated number of sensors is displayed with parameter 2581
UnitNumberCounter .
If reverse counter value (parameter 2581 UnitNumberCounter ) is equal to preset sensor num-
ber stored in evaluator (parameter 200
OMDSensorUnitsNumber
) - verification succeeds, that
is displayed with parameter 2580 UnitNumberApproved = 1.
In case of unit number verification procedure success, ID distribution sequence can be initiat-
ed by evaluator. Otherwise, verification failure scenario should be considered.
7.1.3 Sensor number verification failure scenario
If counted sensor number (parameter 2581 UnitNumberCounter ) value does not correspond to
preset sensor number, stored in evaluator (parameter 200 OMDSensorUnitsNumber ), number
of sensor-units in the network is treated as not approved. This is displayed by parameter 2580
UnitNumberApproved = 0.
In case when parameter 2581 UnitNumberCounter is less than parameter 200 OMDSenso-
rUnitsNumber
, node assignment procedure can be started, and communication in the network
will be handled considering that missing nodes are offline.
In case when parameter 2581
UnitNumberCounter is higher than parameter 200 OMDSenso-
rUnitsNumber
, node assignment procedure cannot be started, and further effective communi-
cation in the network is not possible. This situation is additionally displayed by parameter
2583 CanNetConfigInvalid = 1.
7.2 Automatic sensor ID assignment
Automatic node number assignment procedure in the network is started after unit number ver-
ification sequence succeeded.
Master initiates ID assignment in the network with common designated service message
kNetworkIDDistributRequest
, sent on CAN1 and CAN2. The rest of the ID assignment proce-
dure is performed by sensors themselves.
The ID, assigned to each sensor acts as CAN telegram identifier node number item for further
communication in the network.
Data items within
kNetworkIDDistributRequest message:
•
Actual number of sensors in the network;
•
Masters configuration parameter set CRC value;
•
Masters time and date (Unix time).