How The Data Exchange Works; Data Integrity - HMS Networks Anybus Communicator ABC4018 User Manual

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How the Data Exchange Works

Anybus Communicator - Modbus TCP Server to PROFIBUS DP Device
4.2. How the Data Exchange Works
Figure 2. The Communicator internal memory areas
The data exchanged between the Communicator and the Modbus TCP and the PROFIBUS resides in the
Communicator internal memory buffer.
The Communicator internal memory buffer is divided into two areas: Input data and Output data.
Input Data
This Input data area is read by the PROFIBUS.
The Communicator can handle up to 244 bytes input data.
Output Data
The Output data area is read/written by the Modbus TCP.
The Communicator can handle up to 1500 bytes output data.

4.3. Data Integrity

A snapshot of the process data buffer between the Modbus TCP/PROFIBUS Client and the server interface is used
during the operation of executing all the transactions within one cycle.
When the cycle is completed, the process data available on the server interface is updated and a new snapshot is
created for the next cycle.
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