The main task of the module of IBS100 is to send process data of Interbus-S between the PLC and the controller of Interbus-S host. The output data of Interbus-S is sent from the controller host to the module of IBS100, and next to the table of PLC CPU’s %AI. The PLC CPU writes downs to the module of IBS100 using the table of %AQ, the module of IBS100 transfers this data to the host controller.
The PLC can enthusiastically, throughout ladder program control, construct the process data amount transferred to/from the host controller. Nevertheless, the data quantity to be sent between the PLC and the IBS100 module via the PLC backplane has to be permanent at configuration time of PLC. This amount is defaulting to 32 words for both %AQ and %AI. Mostly for applications, this amount will not require to be modified. If, nevertheless, the module of IBS100 is located in a rack of model 311 with a number of other modules that need registers of %AQ and/or %AI, the user may start to expire of %AI and/or %AQ registers. In this issue, the various registers owed to the module of IBS100 can be decreased to put up the amount of Interbus-S data in fact sent over the network.
In addition, if a major segment of the %AQ and/or %AI data is not used by the appliance, a minor performance increase in PLC ladder implementation time can be recognized by limiting the data sent to/from the module to the quantity that is really used. The value of performance increased is based on the PLC model and the ladder program. The value of %AQ and %AI registers should be set equivalent to the words number to be sent on the Inberbus-S remote bus to optimize system performance. If the data transferred number on the Interbus-S is to be active, the amount of %AQ and %AI registers ought to be set to the maximum value of Interbus-S data.