Modbus TCP Server and RTU Slave simulates Modbus Holding, Input and Output registers 0 to 65535 according to Modbus specification 1.1b3. Simulate Modbus devices to facilitate software development and observe raw data exchange between TCP server and client or RTU master and slave..
This version can simulate error replies, supports up to 8 simultaneous client connections and unlimited Modbus transactions.
Bug fix for Modbus RTU (serial) function
Code improvement in serial port connect/disconnect
Modbus Message analyser now operational for RTU
Ratings and Reviews
perfect for modbus rtu serial testing
i am using this for testing and analyzing modbus rtu with a cheapo usb-serial-rs485 connecter and works great. i had some problems with crashes and the data log window and they were fixed in one day after contacting the developer.
one feature/use which might not be obvious at first is that this is also very nice to "listen in" on the rs485 bus. you can "mute" the app but it will still report what is going on. very helpful for debugging nasty modbus issues
Developer Response ,
Thanks for the feedback.
Great tip on "listening" to Modbus RTU traffic fro debugging.
Just a little side note: listening works only with RS485 ports (multi drop), it does not work with a RS232 ports (you can only listen to one side).
Gets the job done
Good enough as a basic Modbus testing tool. It allows you to create both Modbus TCP and Modbus RTU Servers, and both funciton as expected. There is a nice data log that will show the network traffic. Adding registers manually is a bit of a pain, but there is an option to auto add registers with a default value on read/write from the client. Would like to see the ability to assign labels to registers.
Does not work well….at least in 10.11.3
After downloading and trying Modbus Server (free) and learning it does not work in 10.11.3, I read the info on the Pro version and it indicates it works “10.6 or later.” So, I spent the $3.99 and have wasted a ton of time (and $3.99) trying to figure out how to create 8 input registers. There appears to be no way to (easily?) create and load 8 input registers. I can’t even create and load 8 holding registers. The server does start up and responds to inquiries. However, it’s basically worthless to me unless someone can tell me how to create the additional registers I need to simulate the device for which I’m writing an interface.
The help tool is nicely done, but is of little value, at least with regard to my needs.
I would even be happy to hack the .mbs file that holds the register settings if that information was provided.
Come on Contech—a little help, please!!!
Developer Response ,
I apologise for the bug which blocked CMD-A (add register) from working.
This problem has been resolved in V3.8
With Family Sharing set up, up to six family members can use this app.