116 ï AppendixMailbox Command ReferencesWAGO-I/O-SYSTEM 750I/O Modules6.3.4 Process Image6.3.4.1 Determine the Size of a Slot for Data Transfer in the Master Process Image(SetRemotePiSize, 0x32)With this command, the process image of a remote bus module is limited to nbytes within the master process image. Therefore, the total of all slave processimages in the master may not be larger than the set master process image - 2.This is because two bytes of the total size are necessary for the control/statusbyte and a reserved byte. The size of the master process image can be queriedand configured over the parameter channel. It is contained in the LSB by pa-rameter 0.By downsizing the available process image, the sum of the configured cutoffsmay exceed the size of the master process image. In this case, the initial con-figuration is already invalid. In such a case, the configuration is executed, butthe error value MBX_CMD_INVALID_CONFIGURATION is displayed. Ifthe initial configuration is correct, a command that leads to an invalid configu-ration is acknowledged and rejected with an error.NoteThe process image mapping can also be configured in the slave mode, butdoes not have any effect until it is changed to the master mode.NoteSlots 1 and 13 must be given as parameters in the area 0 through 12.ConditionsMailbox size Operating mode/profile Device role6 12 18 Config. Real-time Ad hoc Master SlaveSaveconfig. Restart● ● ● ● - - ● ● ● -RequestByte 27 26 25 24 23 22 21 200 MBX_SETREMOTEPISIZE1 T -2 MBX_TARGET_TABLE_AND_INDEX3 CUTOFF_N_BYTES
