Don't forget that each console can only receive data from one ISS (at a time). In general, it's not possible to have multiple ISS units reporting to a single console.
...well, according to the service tech at Davis, apparently it *can* be done:
@Old Tele man: I don't think you read my original reply very carefully, because it's not at variance with what Davis say. I've highlighted the key words for you.
The OP was asking about using up nine weather stations to read multiple weather parameters, including eg wind speed and direction, temperature etc at each site. In Davis terms that effectively means using a complete ISS at each site.
It's theoretically possible to do this by having a maximum of 8 ISS units and putting one on each VP2 wireless channel. But the catch obviously is that the console can only listen to
one ISS at a time. (Using an Envoy8x would actually be another option, but that's a whole different set-up and one that I think wasn't seriously being entertained here.)
The question that Davis answered was effectively whether you can have multiple sensors reporting to one console and the answer here is well-known to be yes. What Davis were saying is that it's perfectly possible to downgrade an ISS to, for example, a temperature station and have a console pick up only the temperature data (or eg T/H) from the ISS. In practical terms therefore the secondary ISS is no longer functioning as an ISS, it's effectively just a 6372 or 6382 station. (Actually using a Vue ISS can be more slightly more cost-effective than a 6382 station in this sort of application, though the radiation shield obviously isn't quite as good.)
I repeat, there's no way that you can pick up
full ISS data, including eg wind data, at a console from more than one ISS unit
at a time (other than by going down the 8X route).