This is open source modbus client for Windows and Linux operation systems.
https://github.com/sanny32/OpenModScan
https://github.com/sanny32/OpenModScan
Attachments
-
103.5 KB Views: 11
-
75.2 KB Views: 10
Can u show me finded devices at result list on the right side of the MODBUS Scanner dialog?There seems to be a bug in the scanner: finding the wrong Device ID (node address).
Case in point: The server's IP address is 192.168.1.42; the server's Device ID is 3.
Here's the setup for the scan:
View attachment 3759
Here's the results when the scanner found the server at 192.168.1.42, but at Device ID 10, not Device ID 3.
View attachment 3760
You must be used to using 0-based addressing. This software appears to use 1-based addressing, just like WinTECH's ModScan.Register addresses seem to be off by one though, e.g., to write register 3008 you use register 3009 in Open ModScan.
Are you sure you're not confusing the scanning status (i.e. what device ID it's currently trying to scan) with the actual discovered devices? In your screenshot, the scanning is 100% complete and the Device Id shows 10 because that was the highest Device Id you configured it to scan, not because it necessarily found a device at Device Id 10.There seems to be a bug in the scanner: finding the wrong Device ID (node address).
Case in point: The server's IP address is 192.168.1.42; the server's Device ID is 3.
Here's the setup for the scan:
View attachment 3759
Here's the results when the scanner found the server at 192.168.1.42, but at Device ID 10, not Device ID 3.
View attachment 3760
["human-readable" register number and is 1 more than the "on-the-wire" address"] to me, that just seems to create confusion...You must be used to using 0-based addressing. This software appears to use 1-based addressing, just like WinTECH's ModScan.
Take a look here for more details:
https://control.com/forums/threads/modbus-register-numbering.49844/
Yep, just one of the many quirks of Modbus. You're not the first to be confused by this, and certainly won't be the last. This "off by one" addressing issue is one of the most common mistakes made when configuring Modbus devices.to me, that just seems to create confusion...
It is possible to implement in future version.@SaNNy, if this is indeed the case, perhaps it would be less confusing to remove the values for the scanning fields (Address, Port, Device Id, Scan Time) after, or shortly after, the scan has completed. This would then be consistent with how it looks prior to starting the first scan.
Slave Response Timeout setting only affects the connection to device, not the polling of the device.@SaNNy It seems that the Slave Response Timeout setting in the Modbus Protocol Selections window has no effect (I was only able to test using a serial connection). With no slave devices connected, the Number of Polls counter increments at the rate dictated by only the Scan Rate setting, regardless of the Slave Response Timeout setting (I tried setting it to 250, 1000, and 10000 with no difference).
I don't understand this. What is a "connection" when using Modbus RTU?Slave Response Timeout setting only affects the connection to device, not the polling of the device.
Thread starter | Similar threads | Forum | Replies | Date |
---|---|---|---|---|
Modbus TCP/IP client automation direct productivity 3000 series | Modbus | 5 | ||
A | Modbus TCP/IP Client to Client communication | Modbus | 4 | |
E | Modbus Organization Replaces Master-Slave with Client-Server | Modbus | 5 | |
M | Modbus Server and Client Stack in ANSI C | Modbus | 0 | |
H | Modbus UDP Client | Modbus | 1 |