Hi slaicheng,
I hope not to be too late with this ...
I post each minute 2 fields in one ch. and check for:
- max value
- min value
- missing points (e.g. only 2-3 points recorded in 5 minutes, not the expected 5)
I started "cloning" this blog http://dbrenk.blogspot.com/2015/03/connecting-thingspeakcom-to.html that put the "light in my life" and I can say "make sense" (read thoroughly) I checked he is still posting here.
The solution I use now is based in Matlab Analysis with TimeControl, but as I said for 1 limit React was used and worked by "clonation".
I use Pushingbox (recommended) and Gmail mails. I also hope these 2 services last a very loooooong time 🙂
if you still need more help, ask
Good luck