Hi All,
Our client is considering Ignition SCADA to replace their legacy system. They have approximately 30 RTU devices on an analogue radio infrastructure. This will be upgraded to a digital radio (Type: 4RF) infrastructure using the DNP3 protocol. Each device will be polled for a handful of DNP3 addresses, mainly level, device feedbacks and faults.
I'm aware that the latest DNP3 driver will handle class-based polling. My question is how does the Ignition DNP3 driver manage a network overload. E.g., If all 30 RTUs are polling a particular class will this not potentially cause congestion on the radio network? Is this something that I even need to worry about? I've read a best practices guide from Topserver that suggests a "round-robin" poll approach. Is this possible with the Ignition DNP3 driver?
Admittingly I am a novice with DNP3 as a whole and therefore would appreciate any guidance.
Thanks
Adam
There's not really any way to manage this right now.
I couldn't tell you ahead of time if it will be a problem for your network in practice or not.
Setting up round-robin would require a somewhat complicated driven tag group setup (if using raw reads, not class-based polling) or manually scheduled calls to the "demand poll" scripting function...
I'm hoping that in the future the driver gets some kind of "polling group" feature that allows devices to be assigned to a named group, and that named group only allows for one device to be polling at a time. Waiting to get some support from the underlying DNP3 library that doesn't exist yet before implementing this.
In general, if you need tight control over polling schedules and ordering with Modbus, DNP3, etc... over serial or radio networks then Kepware (Topserver is just a white label of Kepware, don't know why it exists) might be a better choice.
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I don't know from experience, but I've heard that TopServer has better support than direct from Kepware.