viewstat_422 modules communication speed

aldous

Hi,

the Viewstat 422 module seems to require the Aprilaire 8800 to set to 9600 bps and the responds seems to be slow. Is it possible to set the module to use higher serial speed for the communication?


thank you,
Aldous

John Nagy

Raising the baud rate to get the tiny amount of data "sooner" is like using HI DEF in order to see the movie faster.

All of whatever this thermostat has to say will arrive in a fraction of a second at 9600 baud. If you have delay, it's not in the transport.

To our experience, the stats are not "snappy" in giving feedback, but it's at the internal processing level, not the fault of the baud rate.

"I could be wrong, but I'm not." - Charles Barkley

mpullin

I agree with John. It's not a matter of baud rate. Aprilaire is just slow and ugly especially when you have more than a dozen or so tstats on a disty panel. The best argument for Aprilaire climate control is to look at the alternatives.

GregG

AFAIK, one thing these aprilaire stats do is delay their replies by a tiny bit more the higher the tstat ID numbers is. This is a consequence of being an rs485 bus capable system. If you ask a question like T? to all then ID 1 replies first and ID 2 replies next etc,etc. But they are not smart and don't look for each other's replies and send sooner, they just wait (Time*ID) no matter what. So if you haven't already, fill the Tstat ID #'s from 1 up to the max with no gaps, and then set the max tstat ID value in each tstat - they will use this value to know when the last stat has answered a group request if they are going to send async data.

It doesn't help much, but every little bit adds up.

aldous

Thanks everyone.

DHawthorne

Make sure every thermostat is properly configured with not only a unique address but the total number of thermostats on the system. If the total number set on any of the stats is higher than the actual number, the entire buss will wait for the nonexistent stats to check in before doing anything else. They time out eventually, but this can be a major drag on the buss.