If service work becomes necessary the module cannot be exchanged if it is not operated with the default process data length

Recommended action how to exchange a module when service work becomes necessary
The recommended action how to exchange a module when service work becomes necessary described in the following refers to all version of the communication modules and fieldbus function modules listed below.

What happens?
The DeviceNet scanner generates an error message when the DeviceNet system is started. The error message informs the user that the process data length of the DeviceNet master (scanner) differs from the one of the Lenze slave module. Therefore, process data cannot be exchanged with the module affected.

When does the problem occur?
The problem occurs if the process data length set in the module does not match the corresponding entry in the scan list of the DeviceNet scanner. The modules can only be exchanged 1:1 in the field if they are applied as follows:
  • If the modules are operated with the Lenze default settings.
  • If the process data length is specified with every PLC restart via Explicit Messages (DeviceNET parameter channel).

Which products are affected?
E82ZAFD Fieldbus Function Module
E82ZAFVC Fieldbus Function Module
EMF 2175IB AIF Communication Module
EMF 2179IB AIF Communication Module

Possible diagnostics?
The behaviour described before has occurred if the DeviceNet master indicates the node-specific error message 'Wrong process data length' after a DeviceNet slave module has been exchanged.

Short-term measures/recommendations?
The process data length of the modules can be set by means of the DeviceNET configuration software 'RSNetWorks'.

More detailed information on how to set process data lengths is provided in the following AKB article:Data mapping with E82ZAFVC and RSNetWorx for DeviceNet

If the user cannot configure the modules directly via his PLC per Explicit Messaging or via a corresponding DeviceNET configuration software by means of a network adapter we recommend asking the machine builder for replacement modules which have already been parameterised in such a way that they are ready for being uses and to keep some of these modules on stock in order to avoid machine downtimes if the modules need to be exchanged.