How fast is modbus tcp

Rate 0. Dear Sir, I would like to calculate the speed of tranmission of data on above three Bus system. Distance between master and last slave is under meter. Suggestion To thank Quote Answer. It has too low speed. You will get instant values keeping in mind communication speed.

Best regards, Darius. Hello, I can't make precise calculations, but keep in mind if you read data from MODBUS RTU slave which is not consistent then you will need several read cycles, so in my case sometimas I loose ms for one device acquisition. So calculate if you have 30 devices - its 15 seconds until you come back to first device. We speak about bps. Profibus lets you communicate at kbps or 1. Rate 3. There are two very separate things to consider. Taking 1 This will depend on if you are the master or the slave.

If you are master, you control how often the data is requested i. This will be set by how often you toggle the modbus block send input. If you are slave, you will get data at the period the master is configured to send it i. This will be outside of your control. Taking 2 To work out the time taken for the data transfer you must first workout how many bits the data packet consists of this will be different for RTU and TCP as the protocols are slightly different , the bit rate of the link and the packet turnaround time of the slave device the time it takes to handle the request and start to return the response.

Taking a request for 10 holding registers with you being the master as an example. With this, an automation task is solved through the cooperation of intelligent, distributed devices.

The systems require a completely new procedure for programming and engineering. On the other hand, fieldbus solutions are characterized by the mostly unchanged fieldbus protocol. The advantages of these systems are that their use does not require a basic rethinking by the user and that the specifications are stable. These solutions are intended for the fast, reliable transmission of data between field devices and automation devices.

The Modbus services and the object model of the source variant were kept unchanged. The uniform application protocol is common for all variants. The application protocol is independent of the transmission medium that is used. The organization follows the client-server principle. The client initializes a service call by sending a request telegram. Transferring 1K requires almost ten messages. All you have is registers and coils and there is no way to group pump 1 data and logically separate it from pump 2 data.

Because Modbus RTU operates in a half-duplex mode request out — response in, next node and repeat the cycle time through all the nodes varies with the number of nodes. It should be used only in applications where timing and response times are not a consideration.

Modbus RTU devices are wired in a daisy-chained fashion where each node connects to the two wires of the preceding node and the two wires of the successive node. A large number of Modbus RTU devices use screw terminals, which become loose over time. One loose screw terminal in a large network of devices means hours of troubleshooting.