Object dictionary for Node :

Linux_slaveslave

Overview

How to make the object dictionary of the node ? First, use Jaxe (command run_objdict) to edit an xml description file of the dictionary : objdict.xml. Then, run the php program : makeobjetdict.php. You can launch php through a web browser if you have installed a server, or, on Linux, you can launch php in command line : php-cgi makeobjetdict.php. It compute the file objdict.c. Link it to your project.
Note : To define the node id, use in your code the function setNodeId(UNS8 nodeId)

Then the node can be connected to the network. The master must configure it by sending SDO. It will write values in its index, subindex. What to configure ?

• Receiving heartbeats from which nodes ? Waiting time ?
• Emitting heartbeats or not ? time btw 2 heartbeats ?
• Defining a cobId for each PDO receive and transmit
• How to transmit a PDO ? on synchro ? request ? event ?
• What variables to put in each PDO receive and transmit ?
• ...

Number of heartbeat consumers : 1

This means that the node can expect heartbeats sent by 1 nodes.

Number of SDO clients : 1

Usualy, a slave node does not have the use of SDO clients, but today, for the library, you must define one. The Master, which can send SDO to "n" slaves nodes, must define here "n" SDO clients. Remember that in most cases, the SDO protocol is used by the master to configure a slave dictionary or read a value. In this use, the master is the client, and the slave is the server.

Maximum objects in a PDO (receive or transmit) : 8

This is defining how many variables can be transmited in a PDO. (maximum is 8).

For each variable, a table is created, so if you have less room in memory, put a value under 8.

Number of PDO receive : 3

The node can receive 3 PDO.

The communication parameters are defined at index 0x1400 to 0x1400 + 2

The mapping parameters are defined at index 0x1600 to 0x1600 + 2

Number of PDO transmit : 3

The node can transmit 3 PDO.

The communication parameters are defined at index 0x1800 to 0x1800 + 2

The mapping parameters are defined at index 0x1A00 to 0x1A00 + 2

Mapped variables and tables

3 tables are defined for the mapping, starting at index 0x2000, 0x6000 and 0x6200. You must start the mapping at the beginning of one of a table, without holes in index or subindex. For example, variables in 0x2000 and 0x2001 is ok, but variables in 0x2000 and 0x2002 is not allowed, because you are loosing room in memory. It is the same for the subindex.

The access of the variable is by default "rw" (read-write) or "ro" (read-only). A read-only variable cannot be mapped in a PDO receive.

Here are some others rules for the mapping :

• At an Index, you can map a variable at subindex 0x0 or 0x1, as you like.
• To map several variables at the same Index, you must start at subindex 0x1, because in this case, the subindex 0x0 contains the number of subindex.
• You cannot map variables and tables at the same index.
• The mapping of a table is always starting at subindex 0x1.