Eaton XN-GWBR Series User Manual

7 Guidelines for station planning7.2 Maximum station extensionXI/ON: XNE-GWBR-2ETH-IP 09/2011 MN05002007Z-EN www.eaton.com 1757.2 Maximum station extensionThe maximum number of modules within XI/ON station with the gateway XNE-GWBR-2ETH-IP depends on the following factors:• The station extension may not exceed the maximum number of 32 modules.• The maximum permissible number of 192 communication bytes which are transmitted viathe module bus from the modules to the gateway must not be exceeded (see below Table65: Communication bytes and nominal current consumptions of the XI/ON modules fromthe module bus IMB, Page 175).• If the maximum sum of the modules’ nominal current consumptions (see below Table 65:Communication bytes and nominal current consumptions of the XI/ON modules from themodule bus IMB, Page 175) right to the gateway (max. sum Σ IMB = 400 mA) is reached,a bus refreshing module has to be used in order to provide the module bus voltage.To the right of the bus refreshing module, the sum of the modules’ current consumptionscan amount to 1.5 A.For the calculation of the maximum system extension, the following table contains an over-view about communication bytes as well as about the modules’ nominal current consump-tions:AttentionEnsure that a sufficient number of bus refreshing and power feeding modules areused if the system is extended to its maximum.NoteIf the system limits are exceeded, the software I/O-ASSISTANT generates an errormessage when the user activates the menu item [Station] > [Verify].Table 65:Communicationbytes andnominal currentconsumptionsof the XI/ONmodules fromthe module busI MBModule Number ofcommunication bytesNominal currentconsumption from themodule bus IMBXN-BR-24VDC-D 2 –XN-PF-24VDC-D 2 ≦ 28 mAXN-PF-120/230VAC-D 2 ≦ 25 mAXN-2DI-24VDC-P 1 ≦ 28 mAXN-2DI-24VDC-N 1 ≦ 28 mAXN-2DI-120/230VAC 1 ≦ 28 mAXN-4DI-24VDC-P 1 ≦ 29 mAXN-4DI-24VDC-N 1 ≦ 28 mA