Hello. I had a very similar problem. In my case the initialization of the size was wrong
You could try: best regards
Dominik

I understand this. I will try to handle it by myself with a customized callback in the modbus component part. I hope there will be a supported possibility later which allows to return a value based on a the requested address (or to write a value based on the specific address). The difference would b...

thanks for you comments. Please find my comment to 1), 2) and 4) below: I understand your point and it would also work as you suggested: 1) define register areas of holding registers 2) write a modbus task to update holding register continuously, so all holding registers contain valid information in...

Okay thank you for your efforts to improve this ESP freemodbus port. I now use your example you shared and I changed the callback function: eMBErrorCode mbc_reg_holding_slave_cb(UCHAR * reg_buffer, USHORT address, USHORT n_regs, eMBRegisterMode mode) according my wishes. It all works perfectly. The ...

Thanks for the update. Now it works perfectly and I can define several areas of holding registers. But I have some general problems using this library (Modbus TCP-slave): 1) Like in your example: When updating the holding or input register value on read request, the old value is already returned to ...

Hello, yes I am still interested and I would also test it. It might takes some time because at the moment my project works with esp-idf 4.0 so I need to change some things first to be compatible with esp-idf v4.3.
thanks for your update and let me know how I can test it.

Okay interesting.
Did you find any possibility or work around to make several address areas of holding registers for a Modbus TCP slave?
HREG area 1: 0-100
HREG area 2: 1000-1100
HREG area 3: 2000-2100
...

in my case it is a Modbus TCP slave (server).
The problem is, that the prepared library from esp-idf does not allow several areas of holding register areas.

Hello,
okay thank you very much for your reply, very appreciated.
I am looking forward for the new version then.
best regards
DK

Hi, thanks for the information. So it means currently my problem cannot be solved, right? In my opinion it would be very helpful if there was a read and write callback function which is called on each read/write request from the master (independent if rd/wr single or multiple register). In the callb...