SIPOS 5 Flash basics
MODBUS RTU |
Since the late 1970s, MODBUS has been available as a bus protocol for fast, straightforward connection between an (I&C) master and many slaves (actuators, sensors).
In contrast to PROFIBUS, MODBUS has protocols of different lengths for accessing data structures – from reading and writing single bits (–>‘Read Coil Status‘, ‘Write Single / Multiple Coils‘) to reading and writing entire data ranges (–>‘Read Holding Registers‘, ‘Write Single / Multiple Registers‘) and diagnostic telegrams. Each slave does not necessarily have to be polled in cyclical, equidistant intervals.
MODBUS is used globally in industrial automation – configured as RTU (remote terminal unit - implemented in SIPOS 5 Flash), ASCII and TCP/IP.
All process data access (run commands, status information) and assigning of all actuator parameters is supported by the MODBUS slave connection in SIPOS 5 Flash.
Additionally actuator information can be read out (‘Read Exception Status‘, ‘Report Slave ID‘ and ‘Read Device Identifi cation‘ functions).
The physical connection is, in common with PROFIBUS, via RS485 or fiber-optic cable.
