Facing challanges setting up this cli ,the result i keep getting is an incrementing value which is not the static value in my server, ive tested the communication in the WEB UI and i'm getting the correct value

[Richard1200]

root@RUT901:~# ubus call modbus_client.rpc tcp.test '{"id":1,"timeout":10,"function":1,"first_reg":1,"reg_count":"1","data_type":"bool","no_brackets":1,"ip"
:"192.168.2.175","port":"502","delay":0}'                                                                                                                   
{                                                                                                                                                           
        "error": 0,                                                                                                                                         
        "result": "5"                                                                                                                                       
}                                                                                                                                                           
root@RUT901:~# ubus call modbus_client.rpc tcp.test '{"id":1,"timeout":10,"function":1,"first_reg":1,"reg_count":"1","data_type":"bool","no_brackets":1,"ip"
:"192.168.2.175","port":"502","delay":0}'                                                                                                                   
{                                                                                                                                                           
        "error": 0,                                                                                                                                         
        "result": "6"                                                                                                                                       
}                                                                                                                                                           
root@RUT901:~# ubus call modbus_client.rpc tcp.test '{"id":1,"timeout":10,"function":1,"first_reg":1,"reg_count":"1","data_type":"bool","no_brackets":1,"ip"
:"192.168.2.175","port":"502","delay":0}'                                                                                                                   
{                                                                                                                                                           
        "error": 0,                                                                                                                                         
        "result": "7"                                                                                                                                       
}                                                                                                                                                           
root@RUT901:~# ubus call modbus_client.rpc tcp.test '{"id":1,"timeout":10,"function":1,"first_reg":1,"reg_count":"1","data_type":"bool","no_brackets":1,"ip"
:"192.168.2.175","port":"502","delay":0}'                                                                                                                   
{                                                                                                                                                           
        "error": 0,                                                                                                                                         
        "result": "8"                                                                                                                                       
}                                                                                                                                                           
root@RUT901:~# ubus call modbus_client.rpc tcp.test '{"id":1,"timeout":10,"function":1,"first_reg":1,"reg_count":"1","data_type":"bool","no_brackets":1,"ip"
:"192.168.2.175","port":"502","delay":0}'                                                                                                                   
{                                                                                                                                                           
        "error": 0,                                                                                                                                         
        "result": "9"                                                                                                                                       
}                  

[Martynas]

Hello,

Starting from recent firmware versions (>7.13), there was a change in the usage of the ubus modbus command, and it’s now recommended to use the API calls for reading Modbus register data.

However, there’s a known workaround method involving two ubus calls that you can use to achieve similar functionality. This workaround has been outlined in the topics here:

Major issue with new firmware

For anyone that still has this issue basically the solution was to make to ubus calls. One to modbus_client.rpc serial.test then a second one to modbus_client.rpc request_status. The first ubus call just returns an Id value for the modbus request then the second returns the modbus value for that Id value. Here’s a demo code to help: #!/bin/ash REQUEST_ID=$(ubus call modbus_client.rpc serial.test ‘{“id”:1,“timeout”:5,“function”:3,“first_reg”:421,“reg_count”:“2”,“data_type”:“32bit_int1234”,“no_…

Change in ubus command output with latest firmware TRB245/RUT906

Thank you so much Chrish, this is working perfectly nice and are almost as responsive as earlier. You saved my use case with quite many RUT956 devices interfacing Modbus-devices and the ability to keep the firmware updated! Since you pointed out that catching ubus could create an issue, maybe with memory?, i made a test script for tcp.test, doing the job continuously and flawlessly. After running 90k+ calls i cannot see any significant changes in memory use(terminal → top). But maybe you have…

Best regards,

[Richard1200]

much appreciated …
Made an update to version 7.14 and the command seems to be working okay now. not sure if its a glitch or a turn made in the newer version

[Martynas]

Thank you for the update and taking a deeper look. It indeed seems to be working on 7.14 as on previous (<7.13) firmwares.

Kind regards,