5 Connecting the PLC to the gateway using CODESYS5.3 Configuring the system with XSOFT-CODESYS-3Gateway XN-312-GW-CAN 06/16 MN050003-EN www.eaton.eu 67Automatic mapping limitsIf I/O slice modules are added to the CANopen device, the correspondingaddresses will be assigned automatically. A PDO contains a maximum of 8bytes of process data. In XSOFT-CODESYS-3, automatic PDO mapping canbe used successfully until one of the following limits is reached:• The maximum number of PDOs will depend on the number of PDOssupported by the gateway; please refer to ￫ Chapter 10 “Appendix”,page 376.• A maximum of 64 digital input channels• A maximum of 64 digital output channels• A maximum of 12 analog input channels• A maximum of 12 analog output channels• No specialty modulesThis default "mapping" and activation of process data is specified in accor-dance with communication profile CiA DS-301.5.3.4.3 Manual mappingCertain XN300 slice modules provide information that needs to be mappedmanually to unused PDOs. The appropriate subsections in ￫ Section “7Product-specific CAN objects XN300 slice modules”, page 105 contain tableslisting these PDOs for each XN300 slice module. For example, the PDOs forthe XN322-20DI-PD can be found in Table , page 112.In this case, as well as in cases in which you want to change the mapping forthe PDOs, you will need to map the corresponding data manually. The fol-lowing example shows how to add an additional PDO and then add the pro-cess data for the XN-322-20DI-CNT device's counter to the mapping table.▶ Ideally, you should first use default mapping and add the I/O slice mod-ules as devices to the CANopen device before doing any manual map-ping ￫ Section “5.3.4.2 Automatic PDO mapping”.Switching to manual mappingFollow the steps below to switch to manual mapping:￫ If the XN300 station has more input or output channels thanspecified above, or if it includes specialty modules, the processdata objects must be enabled manually(￫ Chapter 5 “Connecting the PLC to the gateway using COD-ESYS”, page 59).￫ For more detailed information, please consult the following doc-uments:• The manual for your configuration tool• The online help for CODESYS, which can be opened bypressing the function key• System description CiA Draft Standard DSP30
