https://control.com/technical-articles/introduction-to-modbus/
In 1979, Modicon introduced a new protocol leveraging the application layer of the OSI model specifically for use with its PLCs. This protocol was called Modbus and became the first widely used fieldbus in the history of automation.
https://control.com/forums/forums/modbus.36/
A community for the Modbus communications protocol - data communication between devices over TCP/IP and over serial line – open and royalty-free since 1979. Visit Modbus.org to download the Modbus protocol specification and implementation guides.
https://control.com/technical-articles/introduction-to-modbus-and-modbus-function-codes/
When industrial electronic devices communicate with each other, they need to use a common communication protocol such as Ethernet/IP, PROFINET, or EtherCAT. Of these communication protocols, Modbus is one of the oldest still in use today.
https://control.com/textbook/digital-data-acquisition-and-networks/modbus/
Developed by the Modicon company ... in its industrial control products, Modbus is a protocol designed specifically for exchanging process data between industrial control devices....
https://control.com/forums/threads/main-difference-modbus-and-modbus.9030/
Modbus is an open network, the complete protocol can be downloaded from Modbus.org or Modicon.com and implemented by anyone as either a slave or master (PI-MBUS-300 is the "bible" for Modbus Protocol).
https://control.com/technical-articles/choosing-an-interface-why-modbus-is-still-around-after-40-years/
Modbus is an open serial protocol based on a multi-drop client/server architecture. In a typical Modbus network, one server communicates with up to 247 clients using either a 2-wire topology or a 4-wire topology in accordance with EIA/TIA-485 ...
https://control.com/forums/threads/modbus-ascii-protocol-standard-definition-or-net-library.55321/
Take a look at the NModbus C# library here: https://github.com/NModbus/NModbus As a general note, though, you are mixing your Modbus terms. Modbus ASCII is a serial-only protocol defined in the Modbus specifications. The other defined serial protocol in the specifications is Modbus RTU, which uses binary encoding instead of ASCII, and is the more commonly used of the two.
https://control.com/technical-articles/how-to-building-a-plc-project-with-modbus-communication/
Modbus is a communication protocol commonly used with input/output (I/O) data to share information at this simple device network level.
https://control.com/technical-articles/so-you-got-a-modbus-tcp-device-what-next
In the Modbus world, there are only two required variables: a function code that tells the receiver what type of data to expect, and the starting address for that request. If it’s output info, you’ll also need to tell it what value to place in those addresses.
https://control.com/forums/threads/i-am-new-to-modbus-looking-for-guidance.49808/
The documentation should have a 'map' of the Modbus registers. The data format (integer, floating point, or ASCII, among others), engineering units and whether the value is read only or read/write is typically included in a Modbus register map. Given that PLC's are custom programmed, the programmer has to enable Modbus registers and define which goes in which register.
https://control.com/forums/threads/origins-of-modbus.44722/
Modbus is a serial based communication protocol that has been widely used in industrial automation industries. Modbus allows for communication between many devices connected to the same RS-485 network, for example, a system that measures temperature ...
https://control.com/forums/threads/modbus-simulator-software-master-client.55304/
For Modbus testing and simulation, here are a few tools that work well: - QModMaster (free, open-source) - good for basic master testing - modpoll (free CLI) - great for scripting automated tests - ModbusSimulator (modbussimulator.com) - combines master + slave with TCP/RTU/ASCII in one tool The key advantage of having both master and slave in one application is being able to simulate the entire communication chain.
https://control.com/forums/threads/modbus-over-ethernet.29872/
Modbus is a protocol. You can use Modbus protocol over Ethernet, it is then called Modbus TCP/IP. Commonly used by Schneider Electric, as Schneider bought the company Modicon, and Modicon originally created Modbus.
https://control.com/forums/threads/modbus-for-dummies.30496/
Also unlike most industrial protocols Modbus is an open protocol so there is lots of information available on how it really works. I would pay particular attention to what the official spec has to say about data table addresses. There seems to be quite a lot of simply *wrong* information about this in many places.
https://control.com/forums/threads/some-understanding-of-modbus.47119/
A mule doesn't know or care what load it carries, whether it's a sack of beans, a keg of gun powder, or a load mining tools. It just carries the load from point A to point B. Like the mule, Modbus doesn't know or care whether the data it carries is process variables (temperature or pressure), switch status, the version number of the firmware, or Shakespeare.
https://control.com/forums/threads/snapmodbus.51096/
Hi All, here to present an open-source multi-platform Modbus suite (libraries and tools). - Native 32/64 bit architecture Intel/ARM : Windows, Linux, FreeBSD, macOS - Full Modbus specifications compliant: all functions are implemented, both in Master and Slave. - Supports TCP, RTU, ASCII and...
https://control.com/forums/threads/modbus-client-application.53172/
This is open source modbus client for Windows and Linux operation systems. https://github.com/sanny32/OpenModScan
https://control.com/forums/threads/modbus-basic-questions.49059/
I've never used QuickHMI, but it would seem to make sense that if you want to access Holding Register 9, then you would reference it as hr9, not hr8 (unless QuickHMI uses 0-based addressing instead of 1-based). More importantly, though, Modbus registers are 16-bit integers, so you should be using the "Ushort" variable type, not the "Byte" variable type.
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