Emerson 0471-0128-02 manual Configuring the SM-EtherCAT module for cyclic communications

5.1.3Configuring the SM-EtherCAT module for cyclic communications

Unlike other Control Techniques fieldbus communication protocols, CoE does not require that any module parameters be changed in order to achieve communications. The baud rate of the network is fixed and the module is automatically allocated an address.

To check that the ethernet cable connected to the SM-EtherCAT module on the drive is connected correctly, look at the LED on the front of the SM-EtherCAT module relating to the connector being used, if this light is a solid green color then a link is established with the master, if this light if off then check the cabling and also check that the master has started communications.

In the master, scan the network ensuring that the SM-EtherCAT module is connected correctly to the master. If the network is configured correctly the SM-EtherCAT node(s) should be visible in the PLC Master.

Decide on the input / output data you wish to send cyclically (objects and/or parameters).

Cyclic data is implemented on CoE networks by using "Process Data Objects" or PDOs. Separate data objects are used for receiving (TxPDOs - from the slave to the master) and transmitting (RxPDOs - from the master to the slave) data.

These PDOs contain the cyclic data (objects and/or parameters), the RxPDOs available are 1, 2, 6 and 22, the TxPDOs available are 1, 2, 3, 6 and 22 (for more information on these PDOs including default mappings please see section 6.1.2 RxPDO mappings on page 21 and section 6.1.3 TxPDO mappings on page 23).

Figure 5-1 SM-EtherCAT PDO configuration

RxPDO1
	0x6040		0x6042		Pr 20.21
	Control word	vl_target_velocity
PLC
TxPDO1				TxPDO6
0x6041	0x6064 position				Pr 18.22	Pr 20.22
Status word	actual value

RxPDO1, TxPDO1 and TxPDO6 will need to be enabled in the master. Once enabled you will need to add mappings to the PDOs.

The format used when mapping objects to PDOs is as follows:

•Index: Object index number (0x0000)

•Sub-index: Object sub-index number (0x00)

•Size: Dependant on the size (in bytes) of the object to be mapped (range: 1-4)

The format of mapping drive parameters to PDO is as follows:

•Index: 0x2000 + menu number

•Sub-index: 0x00 + parameter number

•Size: Dependant on the size (in bytes) of the object to be mapped (range: 1-4)

For example Pr 20.21 would be index 0x2014, sub-index 0x15 and the size would be 4 (the parameter is a 32-bit signed value).

		The values are normally expressed in hexadecimal, so care must be taken to enter the
	NOTE
		correct parameter number.
14			SM-EtherCAT User Guide
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