Concurrent modbus tcp server

[davidbgtx]

I have a Do-More (call it cool) that writes (MWX) 1 other do-more (call it Anneal), and reads (MRX) one do-more (call it Oven). I have created tcp device for each.
I had 3 do-mores each with a MRX to the (Cool) do-more looking at the same coil, using the internal modbus tcp client.
All worked well until I added a fourth do-more with a MRX to the (cool) do-more, and this fourth do-more would give MRX fail warnings.
Increased concurrent sessions on the (cool) do-more to 5 and all is well.
My question is am I limited to 16 do-mores reading the (cool) do-more with modbus, or do I just need to do writes in the (cool) do-more to all the others (then I could use stages so they wouldn't be concurrent. Using modbus instead of peerlink because I have a lot of mixed devices, but they all can use modbus.

[BobO]

Limited to 16 simultaneous connections on the server. Clients are essentially unlimited, and clients can be used with multiple servers, although with a performance penalty.

[ADC Product Engineer]

Just as a FYI, with version 1.4 Do-more can now talk directly to another Do-more using RX/WX and native registers instead of having to do MODBUS or DirectLogic protocols.

[davidbgtx]

Just as a FYI, with version 1.4 Do-more can now talk directly to another Do-more using RX/WX and native registers instead of having to do MODBUS or DirectLogic protocols.

I think I will set it up that way (RX/WX). Trying to decide if whether to put all the rx/wx's in the Do-More providing the info "server", or one rx/wx in each of the do-more's needing the info "clients". Which way would put less of a hit onto the "server" do-more? Do I not have to worry about concurrent sessions using rx/wx? One caveat is sometimes I only want to read write a single bit (say C0) not (C0-7), but that's not a biggie, might just have to move a few addresses around.
I still have to use modbus tcp/ip to each do-more for my sql data collection server, but all the data collection read/writes are handled by the sql server using Kepware.(Kepware is considering building a native driver for Do-More I believe). And some of the Do-More's have to talk to WINPLC's, been using modbus for that also.

[BobO]

Native RX/WX uses UDP, which is unconnected. All of the session management is automagically handled by the driver.