Way to limit simultaneous connections to PLCs?

I hit an issue recently where a Honeywell temperature controller wasn’t responding to Modbus TCP queries. Turns out that the Ethernet “card” inside the Honeywell is so basic is can only handle a couple (maybe 1) connection at a time. I had two Ignition servers polling these controller so whichever one connected first received good data, and the other one just showed “Disconnected.”

Is there anyway I can limit the maximum number of simultaneous connections to a PLC from the Ignition server? To be fair, I don’t know for certain that the Honeywell even CAN handle more than 1 connection at a time, or if Ignition makes more than one connection at time, but if I can manually limit simultaneous connections it help me figure things out (plus there are plenty of other devices that have connection limits and it would be helpful to make sure one Ignition server isn’t about to max out those connections.

The Modbus driver never makes more than one connection at a time.

The drivers that do support it (Logix family for example) will expose some kind of “concurrent requests” setting.

Thanks Kevin! I was worried that in the end it would be an issue of low tech controllers, but wanted to make sure.