Connection issue for EM101+ meter

Greetings Kurumi sir,

We are trying to fetch data from an EM101+ L&T meter but it is showing "Failed to receive data from the meter in the given time". We have tried the following things by researching the old forum discussions,

1. It is an IS 15959 CAT - C3 meter so it is a DLMS meter
2. The cable connection is also correct as per the pinout given by the manufacturer from the RJ 11 connector
3. We are not using an optical head since our application is to fetch data through an RS232 port.
4. We have checked by keeping both the manufacturer settings as Larsen & Toubro and Indian Standard meter.
5. We tried changing the max payload size value by changing from 128 to 512.
6. The interface is also kept in HLDC only since we are using an RS232 port.

Hardwarically we have connected the phase and neutral wire to the meter and connected a bulb on the load side of the meter to check if any data can be read through the rs232 port.

After all these corrections we are not able to even connect the meter with the interface. Please let us know if there are some driver issues is there or else some other corrections need to be made.