Equipments (Devices) > PLC300 > Ladder > Communication Network > CANopen

Operation in the CANopen Network - Master Mode

Besides the operation as a slave, the PLC300 programmable controller also allows operation as a master for the CANopen network. PLC300 characteristics and functions as a master for the CANopen network will be described as follows.

Enabling Function CANopen Master

By default, PLC300 programmable controller is programmed to operate as a slave for the CANopen network. Programming the equipment as a master for the network must be done by using the WSCAN software that also allows the configuration of the whole CANopen network. A detailed description of the WSCAN software windows and functions must be obtained in the menu "Help" in the software itself.

After the master configuration has been created, it is necessary to download the configurations by using one of the product's programming interfaces - refer to the user manual for further information. Once programmed as a master for the network, in case it is necessary to delete said configurations, the function to delete the user program - available in the Setup menu - also deletes the CANopen master configurations.

NOTE!

CANopen network is a flexible network that allows several different ways of configuring and operating. Nonetheless, such a flexibility requires the user to have a good knowledge of the communication functions and objects used to configure the network, as well as knowledge of the WSCAN programming software.

CANopen Master Characteristics

PLC300 programmable controller allows the control of a group of up to 63 slaves, using the following communication tasks and resources:

•	Network management task (NMT)

•	63 transmission PDOs

•	63 reception PDOs

•	63 Heartbeat Consumers

•	Heartbeat Producer

•	SDO Client

•	SYNC producer/consumer

•	512 bytes of input network markers

•	512 bytes of output network markers

Physical characteristics - installation, connector, cable, etc. - are the same for PLC300 operating both as a master and a slave. Address configurations and communication rate are also necessary for the operation as a master, but these configurations are programmed by the WSCAN software according to the properties defined for the master in the software itself.

NOTE!

Input network markers are used to map data in RPDOs, while output network markers are used to map data in TPDOs. They can be accessed in Byte (%IB or %QB), Word (%IW or %QW), or Double Word (%ID or %QD). Nonetheless, their function is not pre-defined and depends on the Ladder application developed for the PLC300 controller.

Master Operation

Once programmed to operate as a master, the PLC300 programmable controller will perform the following steps in order to perform the sequential initialization for each one of the slaves.

1.	By sending the communication reset command to the whole network, so that the slaves initialize with values known for the communication objects.

2.	Equipment identification in the network, through the reading via SDO of the 1000h/00h object - Object Identification.

3.	Writing via SDO of all objects programmed for the slave, which usually include the configuration and mapping of TPDOs and RPDOs, node guarding, heartbeat, besides the manufacturer's specific objects, in case they are programmed.

4.	Error control task initialized - node guarding or heartbeat - in case they are programmed.

5.	Sending of the slave to the operating mode.

If one of these steps fails, communication error with the slave will be indicated. Depending on the configurations, the initialization of slaves will be aborted, and the master will initialize the following slave, returning to the slave presenting error, after trying to initialize all other slaves in the network.

Similarly, if during the operation of a slave, an error in the error control task is identified, depending on the configurations made for the master, the slave will be automatically reset and the initialization procedure will be performed over.

NOTE!

The communication state and the state of each slave can be observed in input system markers.

Blocks for the CANopen Master

Besides the communication and configuration objects made in the WSCAN software, blocks for the monitoring and sending of commands, which can be used during the creation of the application in Ladder for the PLC300 programmable controller, are also available. It is not necessary to use said blocks during the equipment operation, but its use provides more flexibility and facilitates the diagnosis of communication problems during the PLC300 programmable controller operation.