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10.5.1
PDO communication parameter
For each PDO there exists a communication parameter object in which the data how the PDO
will be transmitted or is addressed is stored.
It holds the COB-ID which is the address of the PDO with which it will be sent or received.
It also holds the Transmission type which is defined by the CANopen standard. In the case of
the keypad the Transmission Type is not changeable. The transmission type of every first PDO
is set to event driven, profile-specific. Every other transmission type is set to event-driven,
manufacturer-specific.
The inhibit time of the PDOs is optional it specifies the minimum time between transmissions
of the PDO. Once the PDO is transmitted no other transmissions of the PDO will take place in
the duration of the inhibit time. The Event Time specifies the time period in which the PDO is
transmitted. This affects TPDOs.
The Event Time is specified in multiples of milliseconds. Each time the PDO is transmitted the
event timer will be reset so that after it expires the PDO will be transmitted again. It will however
not be transmitted more often than the inhibit time specifies.
Each object that is allowed to be mapped to the TPDO can be transmitted periodically by the
TPDO. Some objects are able to trigger the transmission of the TPDO independently from the
event timer. This means that when one of the objects is mapped to the PDO the PDO will be
transmitted once the value of the object changes. Those objects are:
̶
0x2014 (button error)
̶
0x2015 (button stuck error)
̶
0x2400 (RCC tilt X and Y)
̶
0x2401 (RCC rotation)
̶
0x2402 (RCC button pressed)
̶
0x6000s1 (keypad button pressed)
10.5.2
Mapping of PDOs
It is possible for the user of the keypad to map objects to PDOs to use the PDO communication
for interfacing with the keypad. Which objects can be mapped to PDOs is defined by the EDS
file. For each PDO there are 2 objects of interest for mapping the parameters. The first object
are the communication parameters. In this object the COB-ID, the Transmission Type, the
inhibit Timer and the Event Timer are stored. The second object holds the information which
objects are mapped to the PDO. These are called PDO Mapping parameters. How to map
objects to a PDO will be described in the following.
The PDO mapping/ remapping is only possible in state pre-operational of
the keypad. If the keypad is set to operational state, PDO mapping cannot
be changed.
1. Deactivating the PDO in question
To deactivate a PDO the most significant Bit of the corresponding COB-ID of the PDO
must be set to 1. This is done in the corresponding PDO Communication Parameter object
Example message for disabling RPDO2:
