Ecat SDO command

[LECA1239]

We try to read and wright data in drive through Ecat SDO command , while ethercat is running / enabled , however when this command comes to execution in PLC , PMAC gets disconnected, and ethercat also becomes non-functional , is there any limitation using SDO while normal PDO exchange is ON.

[Omron Forums Support]

We try to read and wright data in drive through Ecat SDO command , while ethercat is running / enabled , however when this command comes to execution in PLC , PMAC gets disconnected, and ethercat also becomes non-functional , is there any limitation using SDO while normal PDO exchange is ON.

 

I suspect you are issuing these commands repeatedly via PLC, without a Timer(), or delay command. Thus you are clogging the EtherCAT ring with ecatsdo( ) queries, and responses.

 

The ecatsdo( ) command is meant for configuring the EtherCAT system prior to enabling the EtherCAT ring. It is a potentially disruptive, asynchronous command that you are inserting into a synchronous system. Don't issue, ecatsdo( ) commands during closed loop operation, e.g. while jogging motors, or running any kind of motion program.

 

However, during troubleshooting you may be able to issue one, or two in a one shot manner without causing too much of a problem. You will need to test this to be sure that you don't cause a: WatchDog, AmpFault, or mar the surface of the part being fabricated.

 

Try running the PLC as a one-shot and see if this helps. Try placing, "disable PLC n" at the end of your PLC, where n is the number of your PLC. Also, try making use of a, Timer() between, ecatsdo( ) commands to free up resources for synchronous real-time operation.