How Can I Modify My EtherCAT XML Device Description to Include Other I/O?

Updated Jan 12, 2023

Reported In


  • NI-Industrial Communications for EtherCAT

Issue Details

I am using a 3rd party EtherCAT slave device and am importing its XML Device Description according to the instructions provided by NI for Adding Third-Party EtherCAT Slaves in LabVIEW . When modifying an existing PDO mapping to correspond to a new index and name, I am able to successfully deploy these settings and use them with my device. However, when I add a new PDO entry and deploy this XML profile, my EtherCAT device no longer works correctly. How can I successfully modify my XML device profile?


XML Device Descriptions are imported into LabVIEW through the NI-Industrial Communications for EtherCAT driver according to the EtherCAT standard.
  • In order for an XML Device Description to work correctly, it must meet EtherCAT specifications and be supported by the EtherCAT slave device.
  • In some cases, the profile may meet EtherCAT specifications but the slave device will not support that configuration. For example, some devices may have a limit to the total number of bytes that PDO entries can be mapped to.
  • The EtherCAT technical manual for the slave should outline what PDO and SDO communications are supported.
  • If not found in the manual, contact the device manufacturer for the EtherCAT slave about supported mappings.

Additional Information

Erratic XML Device Descriptions may manifest themselves in a number of ways:
  • Failure to import XML into LabVIEW project.
  • Inconsistent scan mode settings between Master and Slave.
  • Error Message indicating that not all slave devices are responding to the master.
  • Incorrect values received from shared variables on slave devices.
  • Unusually long EtherCAT Master deployment from the LabVIEW Project.

When encountering these errors, it is recommended to revert back to a previous version of the XML Device Description that is known to work with the device, preferably a file from the manufacturer. If there are questions about how LabVIEW interprets EtherCAT XML Device Description files, review the resources below and then contact NI Support.