Modbus TCP is a communication protocol for industrial automation technology based on Ethernet. For the most part, Modbus TCP is the direct implementation of the established Modbus protocol (RTU) to a TCP/IP based communication. Existing Modbus applications can thereby easily use a connection-based, secure exchange of process data via an existing Ethernet network
Modbus TCP has the following characteristics:
- Data exchange according to the request/response principle based on TCP/IP connection
- Suitable for simple real-time requirements (cycle times approx.100 ms)
- Based on standard network components (switch etc.) and IT practices
- Very simple, lightweight and universal protocol, basically a transparent implementation of Modbus RTU
- Communication/routing without special gateway across network segments
In contrast to other protocols, Modbus has no problems handling delays in messages that often derive from communication using Modems or wireless Networks. Modbus TCP/IP thus enables reliable remote control, device monitoring and data collection.
AUMA actuators with AC .2 actuator controls support Modbus TCP, allowing easy and flexible integration into virtually any type of network.
- Switched Ethernet
- Data exchange according to client server model:
The DCS as Modbus TCP client requests process data
from the field device as Modbus TCP server
(simple master/slave, polling procedure)
- Device classes:
Server (field devices)
- IP-based addressing in compliance with IT practices
- Uses modified Modbus RTU data telegram with Modbus Application Header
Actuators with Modbus TCP
- Available for SA multi-turn actuators and SQ part-turn actuators with AC 01.2 actuator controls
- 1 Ethernet port 100BASE-TX (100 Mbit/s) for star wiring
- Connection via M12 connector or RJ-45 connector
- IP settings via DHCP or operating software
- Simple wiring by means of auto negotiation,
- cross over and polarity
- Process data input/output completely represented in Modbus registers.
Refer to Modbus Device Integration Manual
- Classification of diagnostic actuator signals according to NAMUR NE 107
Commissioning & communication
AUMA actuators with Modbus TCP interface integrate smoothly into network infrastructures and can be identified and addressed by means of their IP address – similar to the PCs within a local network.
Just few steps are required to integrate an AUMA actuator into a Modbus TCP environment. First, the IP address is assigned via the integrated web server. The Modbus Register requests for process input and output data are configured using the system tools of the DCS.
For real-time requirements, the network utilisation has to be scheduled and managed switches have to be used.
Spare parts list