PROFINET Encoder Interface

PROFINET is the communication standard for automation of PROFIBUS & PROFINET International (PI). Among its several features the following characteristics substantiate the usage of PROFINET:

PROFINET is 100% Ethernet compatible according to IEEE standards and adapts to circumstances in the existing plant thanks to its flexible line, ring, and star structures and copper and fiber-optic cable solutions.

PROFINET includes intelligent diagnostic concepts for field devices and networks. Acyclic diagnostic data transmission provides important information regarding the status of devices and network, including a display of the network topology.

PROFINET integrates automatically reacting redundancy solutions.

Communication takes place over the same cable in all applications, ranging from simple control tasks to highly demanding motion control applications. For high precision closed-loop control tasks, deterministic and isochronous transmission of time critical process data with a jitter of less than 1 μs is possible. data with a jitter of less than 1 μs is possible.

Besides the conventional automation structure consisting of a controller and its field devices, hierarchical structures with intelligent field devices and the shared use of field devices and input modules by multiple controllers can also be realized.

PROFINET is an Industrial Ethernet standard merging plant automation with other enterprise IT resources. It provides comparable functionality to PROFIBUS. Established IT standards are employed as basis of communication: TCP, UDP, and IP. XML is used as description language for device profiles (GSDML files).

Two ways of using PROFINET are available: PROFINET IO, similar to PROFIBUS DP as a distributed I/O system and PROFINET CBA as a modular component based system for larger systems.

• PROFINET offers scalable communication for different applications in industrial automation:
• PROFINET NRT (non real time) is suited for non-time-critical process automation with clock rates of roughly 100 msec.
• PROFINET RT (real time) offers a communication channel with optimized performance (10 msec clock rate) for most factory automation tasks
• PROFINET IRT (isochronous real time) employs special communication hardware to enable clock rates of less than 1 msec and a jitter precision of less than 1 μsec. This channel is mainly of use for motion control applications.

PROFINET IO uses a view of distributed I/O similar to PROFIBUS DP. IO controllers (e.g. PLCs) run an automation program, IO devices (e.g. absolute encoders) are remotely assigned field devices, and IO supervisors (e.g. programming devices) are used for commissioning and diagnostics.

The engineering of PROFINET IO is done similar to PROFIBUS. The field buses (i.e. Ethernet topologies) are assigned to control systems during configuration. The IO device is configured in the actual system based on the contents of its GSDML file. After completion of the engineering the installer loads the data for the expansion into the IO controller (PLC) and the IO controller assumes data exchange with the IO device.

An IO device is addressed within PROFINET (and also possibly by external IT components) through its IP address. Data can be exchanged from the IO controller to the IO device (and vice versa) cyclically (for process data). Apart from this, parameter data can be exchanged acyclically during engineering of the IO device or by the use of PLC programming blocks.

POSITAL offers absolute rotary encoders with PROFINET interface based on magnetic and optical technology. These state-of-the-art rotary encoders provide a resolution of up to 65536 steps per turn (i.e. 16 bit single-turn resolution or 0.005°) and with the multiturn models up to 16384 revolutions (i.e. 14 bit multiturn) can be measured.

Owing to the highly developed filtering ability of the Product Finder the customer is able to configure the encoder(s) needed within seconds. Hence, the customer can select the underlying technology of the encoder (magnetic or optical), various flange and shaft combinations and connection types. IXARC PROFINET encoders of POSITAL are available with shaft and connector seals rated at up to IP67 level and with stainless steel housings.

IXARC PROFINET encoders of POSITAL provide the customer the opportunity to program resolution, time base and filter for velocity, preset, counting direction and IP-Address. In addition to transmission rates up to 100 Mbit and internal cycle time down to 1 ms the IXARC PROFINET encoders of POSITAL incorporate further features such as round axis and flashing LEDs.

• Integrated Boot loader for customer firmware upgrades
• Round axis (Endless shaft)
• Neighboring detection
• Engineering identification call
• Different filters for velocity
• Used PROFINET Encoder Profile V4.0/V4.1

The IXARC rotary encoder of POSITAL with PROFINET interface can be programmed according to the needs of the user. The GSDML file pertaining to the rotary encoder has to be installed in the used PLC engineering software tool.

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PROFINET System Description