Andrei.s

Hello everyone, We want to make Unslave the perfect programmable Modbus simulator. Since publishing, one of the most requested features has been the he ability to change the configuration "on the fly". Today we are releasing Unslave 3.0 with a buit-in HTTP JSON API to support this use case. The API is intuitive and just works. For example this request will update a register value:   PUT http://localhost:9000/slaves/1/registers/HR0 content-type: application/json { "value": 1234 }   The tool is still completely free. You can learn more and downlod unslave here:  Modbus Slave Simulator Please do get in touch if you have any feedback.

All right, sorry about that.

  I have already addressed the text configuration issue earlier. Although it works really well for many people, we do have a modern cross-platform GUI and HMI builder in development for Unserver. As for the simulator tool - we made it for ourselves because the alternatives didn't work for us (for the reasons I mentioned). We uploaded it in hope that it could be useful to others, free of charge. Enough developers have downloaded it, so I guess it was worth it.  Unfortunately, quite often people on the internet feel the need to hate/criticize something just because they don't need it personally. 

Well, text-based configuration is in fact preferable for many users, especially the programmer types. Some of the reasons are: you can make huge changes quickly via copy/paste and search/replace you can search and navigate large configs easily compare different versions of the file you can comment/document settings inline to completely change the setup, you simply specify a different file you can track changes via git or other source control solution you can generate configuration programmatically Those things are important for some users, including us, which is why we created this simulator and made it available for free No software is fit for everyone, obviously. To many users a GUI is more familiar, and therefore easier to use.  

  A new free Modbus RTU/TCP slave simulator tool - Unslave - has been released. It is focused on simplicity, usability and ease of setup. Instead of a GUI it supports flexible JSON-based configuration, where you setup slaves like this: "slaves": {     "1": {         "isOnline": true,         "registers": {             "HR0": 1,             "HR10": "0x0A",             "C0": true,             "C999": {exception: 3}         }     } } This type of configuration has great benefits - you can easily switch between different setups by specifying a different configuration file: unslave.exe newConfig.json You can put the configuration under source control and track changes. Unslave lets you configure any number of slaves, setup values of every Modbus register, setup Modbus exceptions. In addition, Unslave displays and write to a file the logs of all communications on the link. This is very useful for debugging: 2017/06/06 17:21:54.310 - TRACE: Byte received: 1. Total: 1 2017/06/06 17:21:54.310 - TRACE: Byte received: 3. Total: 2 2017/06/06 17:21:54.310 - TRACE: Byte received: 0. Total: 3 2017/06/06 17:21:54.326 - TRACE: Byte received: 60. Total: 4 2017/06/06 17:21:54.326 - TRACE: Byte received: 0. Total: 5 2017/06/06 17:21:54.326 - TRACE: Byte received: 1. Total: 6 2017/06/06 17:21:54.342 - TRACE: Byte received: 68. Total: 7 2017/06/06 17:21:54.358 - TRACE: Byte received: 6. Total: 8 2017/06/06 17:21:54.363 - INFO: Modbus frame received: [1 3 0 60 0 1 68 6] 2017/06/06 17:21:54.363 - INFO: Reading value: 1HR60 = 14119 2017/06/06 17:21:54.363 - INFO: Modbus frame sent: [1 3 2 55 39 238 110] Updated Sep 17, 2017: Since version 3.0 it's possible to update slave configuration at runtime via an HTTP API, for example: PUT http://localhost:9000/slaves/1/registers/HR0 content-type: application/json { "value": 1234 }