CODESYS - the IEC 61131-3 automation software

EtherCat revocering from disconnection

Question:
Which steps are needed to recover from disconnected slaves

Answer:
There are two use cases:
1. IEC application should care on restart / error handling
xRestart on Master is needed
2. restart of slaves is done automatically:
The EtherCAT Master provides an option to restart the fieldbus:
Master Configuration, Master: Checkbox: Auto restart slaves
3. Optional Slaves are possible (this is a tag 'Optional') in the slave config

Question:
EtherCAT Error detection in IEC
Answer:
Master:
Diagnostics Message can be read within the Master configuration tab.
Same in EtherCAT_Master.m_sLastMesage

Slave:
Slave State can be read within the Slave configuration tab. Diagnostics Current State
Same with SlaveName.wState (call of the slave instance is required)
Example:

EK1100(); // Name of the slave = "EK1100"
      EL1004();
      EL2008();
      IF NOT EK1100.wState = ETC_SLAVE_STATE.ETC_SLAVE_OPERATIONAL THEN
      // do something
      END_IF

Snippet:Snippet:


A very good example is the ethercat example in the CODESYS store: http://store.codesys.com/ethercat-example.html#Support

(* Get some information of the slaves and master. It is possible to go through all masters and slaves
   and get information about them. *)


(* EtherCAT_Master is an instance of the IoDrvEtherCAT function block.*)

(* The number of active slaves *)
uiActiveSlaves := EtherCAT_Master.NumberActiveSlaves;

(* Get the ETCMaster *)
pEtcMasterFB := EtherCAT_Master.Master;

(* The number of SDO's *)
iSDOCnt := pEtcMasterFB^.GetNumberOfSDO;

(* Go through all Slaves *)   
pSlave := Ethercat_Master.FirstSlave;



WHILE pSlave <> 0 DO 

   (* get the address of the current slave. This can also be found under the  device in the "Slave" tab. *)
   uiSlaveAddr := pSlave^.SlaveAddr;
   
   pSlave^();
   (* Get the state of the slave *)
   (* With pSlave^.SetOpMode(ETC_SLAVE_STATE), the state can be set.*)
   IF pSlave^.wState = ETC_SLAVE_STATE.ETC_SLAVE_OPERATIONAL THEN 
      ; 
   END_IF 
   
   pSlave := pSlave^.NextInstance; 

END_WHILE

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But we can’t locate the actual Boolean Trigger variable?

You can find the trigger var, if you change the Trigger to “Rising edge” :

you can define any bool var and map the var like any other in/output within the IOMapping for this channel.


What is the scope of the trigger boolean?
Yes
Will it cause just one channel to be written?
Yes

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Question:
How to reset the Master in IEC:

Answer:
Do not use auto restart option and IEC code at the same time.
Use a rising trigger to reset the Master with xReset.

      Ethercat_Master.xRestart := xReset;
      Ethercat_Master();

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In a mixed application with Ethercat and Modbus masters, you see an influence on Modbus update to Ethercat task / sending frames- How could this be avoided?

You need a proper seperation of the use of the modbus io's and ethercat io's according to the task which does the buscycle update:

1. Set Ethercat master in 'PLC Settings' as' Buscycle Task' - and Ethercat io's are only used in ethercat task context (in that case in PLC_PRG)
2. specify on Modbus master the update task for Modbus - and Modbus io's are only used in Modbus task context ( in that case in ModbusPRG)
3. Check if these rules are ok with 'task deployment' tap - Rule: Ethercat io's are only updated in the Ethercat task - Modbus io's are only updated on the Modbus task context - this you see with the red cross on each used io.
check online help for 'bus cycle'


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