![modbus rtu vs modbus tcp modbus rtu vs modbus tcp](https://profinetuniversity.com/wp-content/uploads/2018/04/profinetallindustries_modbus.png)
#Modbus rtu vs modbus tcp update#
Speed is also quite fast with PROFINET as typical IO devices can run at 1ms update times with minimum cycle times from the standard of 31.25uS with the fastest motion control devices.
![modbus rtu vs modbus tcp modbus rtu vs modbus tcp](https://m.media-amazon.com/images/I/51h-r8d2WyL._SL1000_.jpg)
This is handled by each device being a provider of data, and a consumer of data at the same time, the controller sends the output data, devices send inputs. With PROFINET IO full duplex, each device sends its data on its own without waiting for the partner thereby taking advantage of the Ethernet standard.
![modbus rtu vs modbus tcp modbus rtu vs modbus tcp](https://www.controlglobal.com/assets/Uploads/1812-Feat3-Fig1-650-compressor.png)
In addition, Modbus TCP packs its IO data and wraps it inside of a TCP/IP message, which makes transfer time longer. A client must first send a request to a server, then the server answers this request for every transaction. Half duplex is a request/reply or ‘polling’ type of communication that makes the communication slow and laborious. You may ask what is big deal with that? Well, one is the fact that Modbus TCP uses half duplex communications at Layer 4 of the OSI model while PROFINET uses full duplex at Layer 2. PROFINET uses Ethernet for real time data exchange with a provider/consumer model whereas Modbus uses TCP/IP with a client/server model. When it comes to a comparison of speed and determinism, PROFINET is the clear winner. At the end of the comparison, we’ll show a table highlighting the main points for quick reference. In this article, we’ll explain how PROFINET and Modbus TCP compare head to head in order to help you understand the differences between them. Often, when we talk with customers, they ask how PROFINET compares with other network protocols.