Communication Between Plc And Motion Terminal; Numerical Representation; Structure Of The Process Data When Operating A Motion App - Festo VTEM Manual

Function
3.5

Communication between PLC and Motion Terminal

The communication between the higher-order controller (PLC) and the Motion Terminal controller is
based on input and output data of 8 × 6 bytes from the CPX terminal. Each of the maximum 8 valves on
a Motion Terminal is assigned 6 bytes of input data (PDI) and 6 bytes of output data (PDO), regardless
of the actual number of valves.
Fig.16
Depending on the current operating mode of a valve, the following functions and content can be
transferred using the process data:
– Start/run/exit a Motion App è 3.5.3 Running a Motion App.
– Parameterisation of input modules using the PLC è 4.3 Setting sensor parameters.
– Parameterisation of the Motion App using the PLC (parameter download) è 4.1 Setting system,
application and tuning parameters.
– Reading the configured Motion App (parameter upload) è 4.2 Reading out system, application and
tuning parameters.
– Reading of system data and measurement values è 3.5.4.2 Information on the status of the Motion
Terminal (info channel).
– Reading of diagnostic information and acknowledging errors è 3.8.3 Diagnostics channel in
transfer mode.
Not all tasks are possible via the process data range of non-existent or unused slots. Only tasks that
are not valve-related can be executed, such as parameterisation of input modules, reading of system
data and measured values as well as diagnostic information.
3.5.1

Numerical representation

Setpoint values and actual values, as well as parameters, are represented within the process data as a
two's complement value in the format "16 bit signed integer" (signed int16).
3.5.2

Structure of the process data when operating a Motion App

Description of the process data when operating a Motion App (è 3.5.3 Running a Motion App).
36 Festo — VTEM — 2021-05f