The TRH at 250m went out last night for about an hour, right as the checker script was power cycling it because the temp was high:

/var/log/isfs/dsm.log:May  1 01:34:50 250m root: temperature is -61.48 . Power cycling port 5
/var/log/isfs/dsm.log:May  1 01:34:54 250m root: temperature is 168.51 . Power cycling port 5
/var/log/isfs/dsm.log:May  1 01:39:54 250m root: temperature is 168.59 . Power cycling port 5

It came back on its own. Then this morning the Ifan value went to 0.  This could have been because I was testing rserial at that time. I see some of the characters I was typing in the TRH output, such as "|fgre".  So perhaps I caused this second issue.  At 16:48 UTC I power cycled the TRH and Ifan came back.

2015 05 01 16:14:38.1284       1      37 TRH32 9.30 97.48 39 0 1226 201 124\r\n
2015 05 01 16:14:39.1384    1.01      37 TRH32 9.30 97.48 39 0 1226 201 124\r\n
2015 05 01 16:14:40.1384       1      37 TRH32 9.30 97.48 38 0 1226 201 120\r\n
2015 05 01 16:14:40.5740  0.4357      38 \rTRH32 9.30 97.48 38 0 1226 201 119\r\n
2015 05 01 16:14:42.1484   1.574      37 TRH32 9.30 97.48 38 0 1226 201 119\r\n
2015 05 01 16:14:43.1584    1.01      37 TRH32 9.30 97.48 38 0 1226 201 119\r\n
2015 05 01 16:14:44.1584       1      37 TRH32 9.30 97.48 38 0 1226 201 119\r\n
2015 05 01 16:14:44.6040  0.4456      44  f|freTRH32 9.34  97.49 38 0 1227 201 118\r\n
2015 05 01 16:14:47.2784   2.674      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:48.2784       1      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:49.2884    1.01      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:50.2884       1      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:51.2984    1.01      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:51.5941  0.2956      35 \rTRH32 9.30 97.04 0 0 1226 200 0\r\n
2015 05 01 16:14:53.3084   1.714      34 TRH32 9.34 97.49 0 0 1227 201 0\r\n
2015 05 01 16:14:54.3084       1      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n
2015 05 01 16:14:55.3184    1.01      34 TRH32 9.30 97.48 0 0 1226 201 0\r\n