Hi All,

A very good explanation is provided in this website in chapter 16 about modeling a network, devices and communication among devices.

Queries:

1) In the example given in chapter 16 for network, which device implements the entities - network, device, connection ? Is it "area controller" or "server" ?

2) Can Haystack client discover these modeled entities i.e. network, device, connection ? If yes, how? Reason for asking this query - Haystack client performs Haystack operations on site, equip and point. Also Haystack does not define any relation between site, equip with network, device. In this case, can client really discover this ?

Thanks in advance for your comments

That part of Haystack is just experimental. If you want to use it, its just modeling, not related to any network protocols

We use the network connection on some of our projects,

1) As Brian mentioned, It's simple modelling of assets. 2) Clients can query for these entities using readById or readByFilter ops. There is nothing stopping you adding equip and siteRef tags to a device in the chapter 16 example e.g. field controller

Thanks for comments. I understand that more tags can be added as needed to this model.

I think of modeling to be useful in a scenario where Haystack server hides number of end-points (BACnet, Modbus, etc.) behind it.

In such a case, Haystatk client can review this model and understand the hierarchy. This hierarchy might be helpful to client in setting expectations.

But then Haystack standard, as of now, does not mandate anything on this front.

For now, I assume that an "equip" Haystack entity can also have a "device" tag associated with it.