Hi,
Thank you for contacting Teltonika Crowd-support forum. Please find our response below.
I can see in the screenshot that you are using number of registers as 1. According to the Modbus wiki article, you need to have 2 registers to read the GPS latitude coordinates value. Please change the number of registers to 2 and also change the data format to HEX.
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=10758992646622198545)
You can see that I received the GPS latitude registers values as zeros, because my GPS is not enabled. However, I can still read the values from Modbus register.
Related to error you received, please follow the below steps:
1. Go to QModMaster and click on Disconnect icon.
2. Click on Clear table button.
3. Click on Reset counters button. (Please see the picture below for step-by-step instructions):
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=954941826294116357)
4. Set all the values as described earlier in the first picture and click on Connect button.
5. Click on Read and Write button to read the values.
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=4376352382362049781)
You might need to repeat the steps again and check for Modbus Slave IP and Port.
Hope this will help.
Regards
Ramandeep