Hooking up to 14 devices in modbus

[tmoulder]

I love that I can now connect to more than 4 simultaneous devices on modbus TCP!  But I also have a project coming up where I would need to hook into, say, 14 of them. As such, what is the firm-and-fast, not-to-exceed number of modbus devices I can connect to simultaneously on TCP?

 

Thanks!

TM

[Cara Bereck Levy]

We have run field-testing hooked up to 32 devices, and everything worked just fine.

It is, as of right now, not officially limited to 32, but I would not recommend more that at this time, so if you need more, let me know.

 

So, that's twice 14 plus 4 

[Flex727]

I've never gotten an answer to the question as to why the Vision PLCs were limited to 4 simultaneous connection (4 available sockets). Is it hardware or software? And since it was so definitive with the Vision PLCs, why don't you have a definitive answer with the UniLogic PLCs?

[Cara Bereck Levy]

Yes--it's a hardware limitation.

The whole UniLogic architecture is different. Sockets are virtual--a whole different ball game...league, really 

[Gravshin Andrey]

In Visilogic I could dynamically add new slaves, changing the variable address of the device. In Unilogic address is constant. In addition there is no possibility to copy slaves. If I add slaves with a stock, how to enable/disable poll devices?

[Ofir]

Hi,

In the future we will add the option to copy slave and have HMI variable that the user will be able to enter the slave ID/IP.

Currently for each slave you configure in UniLogic, in its properties you can find a parameter "Active" - you can link a bit to this parameter and then you can disable/enable a specific slave.

You can also set "Active" bit for each one of the MODBUS commands.