Modbus TCP Locking Up?

[marksji]

I've been using a great little program for iOS devices called Scada Mobile and now Modbus Gem (stripped down Modbus only version) that basically lets you turn an iPad/iPhone/iPod Touch into a simple HMI. Its been a great program and I really really like it, but I've had a recurring issue with it locking up from time to time.

I got in touch with the developer, really nice helpful guy, and it appears that the ECOM100 has a tendency to flake out on too many Modbus connections. Where I generally hit the problem is when I'm working on something in SM and updating the program frequently; each time the program is updated it drops the connection to the ECOM100 and then starts the connection back up after re-parsing the source file. This leads me to wonder how many concurrent Modbus connections the ECOM100 can handle and also to wonder what is supposed to happen when that limit is exceeded. Should the connection just be refused or should the oldest non-active connection be dropped?

Anyway, any insight is greatly appreciated

[MikeS]

current firmware allows for 12 concurrent connections, older firmware allowed 4. The oldest inactive is closed when a connection request is received. I believe that if all connections are used when a new connection request is received that we NAK the request.

Is there anyway to make sure that the SM software connections are going away when you make a software change? It could be that the old connections are still around and once you hit the limit of 12 the wheels start coming off.

[marksji]

Could be. I can try exiting SM and seeing if that helps...