Modbus TCP slaves not connecting

Official Hardware Opta
1

I as the title says I can not get more than 3 slaves connected at the same time! To my OPTA client ( I have 11, x1 weinview HMI and x10 Mega/W5500) they all connect singularly. I have increased the polling time to 20000m/s, with no improvement. The only positive thing is the HMI always connects, it’s the mega/w5500 that are failing? Anybody got this type of system up and running?

2

Hi @MartinKirkby . This is most likely the low socket limits set in the default Arduino mbed build. A number of issues/PRs have been raised previously but have not received attention.

3

@steve9 Is it possible to increase the limit if using the PLC IDE runtime?

4

Hi, I've no idea as I'm not familiar with the OPTA or the PLC IDE.

I use the GIGA R1 and changing the config and rebuilding the libmbed.a it uses sorts the sockets issue for me. I'm aware it also fixes the same problem for the Portenta H7 but, as I say, OPTA and PLC is a mystery to me.

I suggest raising a support request with Arduino (https://www.arduino.cc/en/contact-us)

5

Hi Guys just an update, I moved over to Codesys with the plan to buy an Opta/Codesys version. I had a RevPi which is Codesys compatible and I have to say the experience is night and day​:smiling_face_with_sunglasses:. All my Modbus slaves talking so my project is just a “proof of concept” right now but progressing again. If I can get my hands on an codesys Opta it’s still my hardware of choice.