CANopen SDO Client Channel Instance

This block defines a CANopen SDO client channel.

Block ID

Library

motohawk_canopen_lib

Description

This block creates a FIFO CANopen client transmit queue. The number of entries in the queue is defined in the SDO requested queue size parameter. SDO client upload and download requests will be placed in this queue for transmission to servers with the Node ID defined by this block's input port.

The node ID is updated when the client channel block executes. The node ID is not saved when the client request is queued, it is retrieved when the queued request is transmitted. It is therefore not recommended that an application make runtime changes to the node ID unless it is sure that there are no SDO client messages pending transmission and the CAN open instance is not waiting on a response from a server.

There can be up to 127 SDO client channel blocks associated with a single SDO client instance. It is not recommended to use the same Node ID value in multiple SDO client channel blocks.

COB ID base values shall comply with CANopen specification :

First 7 bits must always be set to '0'.
If CAN id type in the CANopen instance is set to standard the following value is allowed :

COB-ID base client->server : 0x600
COB-ID base server->client : 0x580

If CAN id type in the CANopen instance is set to extended the following values are allowed :

COB-ID base client->server : 0x600 and any value equal or greater than 0x800
COB-ID base server->client : 0x580 and any value equal or greater than 0x800

SDO requested queue size defines how many SDO requests sent by SDO download and SDO upload blocks can be queued before rejecting additional requests to queue SDO client communication requests. A request is kept in the queue until a response from another node is received or the timeout is met (timeout parameter is set in SDO client block).

It is recommended that client channel be used for peer-to-peer communication. Only one server and one client should communicate over single channel.

Block Parameters

Parameter Field	Values	Comments/Description
SDO Client Reference	String	Name of associated SDO client.
Channel Name	String	Unique name of SDO client channel.
COB-ID Base Client->Server	Numeric	COB-ID base of this SDO client's client to server ID.
COB-ID Base Server->Client	Numeric	COB-ID base of this SDO client's server to client ID.
SDO Requested Queue Size	Numeric	Requested size of SDO client channel queue.