HI, I’m having hard time to setup my Modbus-RTU network. On my slave, I see TX+ and TX- light blinking, which means there is some traffic on the network. On the Anybus module, the light subnetstatus goes from red to flashing green to red again and so.
What can I check more to get the communication working?
Thank you
This is my first time with Modbus RTU.
More informations here:
I want to speak with a Blue i technologies HG-602. Here is the table from the HG-602 manual.
Here is my config
Hello,
I do advise you review the MODBUS protocol for understanding functions and communication I have found simply modbus to be a great tool
https://www.simplymodbus.ca/TCP.htm
What have you set up for Commands?
You can export your configuration file, and attach it to this post.
I Have attached the configuration I have.
Chlore_3.cfg (16.0 KB) Chlore_3.cfx (17.7 KB)
I saw a post from your collegue, that maybe the parameter address is not the same number as modbus adress. I am trying to understand, but I don’t find the post anymore.
Hello,
Given the number of functions you have, it could be possible that some are experiencing exception code error.
I would run the device, and check the logs for any exceptions codes. You can use the above link to verify which command is receiving the error and what the corresponding error is.
-Kevin
Hi Kevin,
I tried to send manual request to the device. I can communicate with it, but I receive a weird response.
I’m looking on the manual you sent, but, I don’t understand why I receive 84 as function code.
And, I don’t understand what Error Check sum do I need to enter
Hello,
As stated before, i highly suggest reading through the Simply Modbus to have better understanding on MODBUS.
THe x84 denotes an exception on Function code 4.
The exact error is x02, which is as follows;
(02 hex)
Illegal Data Address
The data address received in the query is not an allowable address for the slave. More specifically, the combination of reference number and transfer length is invalid. For a controller with 100 registers, a request with offset 96 and length 4 would succeed, a request with offset 96 and length 5 will generate exception 02.
It looks like you may not be requesting the correct amount of data.
Any update on this issue?
Hi Kevin,
Yes I found out my issue.
I was too focus on Offset and stuff like that.
Finally, the wizard on the anybus software wasn’t creating the parameter with the good parameter number (maybe an error on my side), so I change all parameters to the right decimal parameter number and it was working.
Thank you
Nicolas Desjardins
Spécialiste Sénior du développement en automatisation /
Senior Automation development specialist
QUALTECH SOLUTIONS
1880, rue Léon-Harmel, Québec (Québec), G1N 4K3
Tél.: 418.686.3802 ext. :217
Sans frais | Toll free: 1.888.339.3801
Hello,
Excellent! I am glad this issue is resolved.
-Kevin
