The observers version of XMET is a condensed version of [big] xmet
and displays a graph of temperatures over a
two-hour time period. Instantaneous values are displayed, as
well as the following values on the graph, which is updated
- dewpoint maximum (blue line)
- primary mirror temperature, actual (yellow line)
- secondary mirror temperature, actual (magenta/pink line)
- outside air temperature, minimum (white line)
There is a second line graph which displays two-hour's worth of outside humidity (green line) and dome humidity (dull yellow line). Both graphs are updated every minute.
The 'stop-lite' buttons on the right side of the display warn if
the dewpoint is approaching the specified temperature (e.g.,
primary or secondary mirror temperatures or outside
temp). These calculations are based on instantaneous data:
- green: the dewpoint is 5 degrees or more below the specified temperature
- amber: the dewpoint is between 2 and 5 degrees below the specified temp
- red: the dewpoint is dangerously within 2 degrees below the specified temp
- 'pri-dew' : the difference between the primary mirrtemp and dewpoint
- 'sec-dew' : the difference between the secondary mirrtemp and dewpoint
- 'out-temp': the difference between the outside temp and dewpoint
Instantaneous values are displayed for dome temperature, barometric
air pressure, wind speed and wind direction.
There are no line graphs displayed for these values.
Warning text displayed in the red 'Alarm' box indicate the following:
- 'NO MET DATA' : means the met VME crate is possibly down or the tcl scripts are not running (see Trouble-Shooting Section below). When this happens, no data values or appropriate stop-lite warnings will be displayed. You will notice that the linegraph trends may 'spike downwards'. The data labels will also turn red.
- 'STALE GE DATA; Check TCL Scripts' : means that the data has not changed for a while (see Trouble-Shooting Section below.)
- 'INVALID GE DATA' : dewpoint, outside air, and outside humidity will turn red.
- 'GE CLEANING': means that the GE unit is going through its daily cleaning cycle. You will not see GE dewpoint, outside air, and outside humidity since these values should be ignored during these times. The appropriate line graphs will spike downward.
- 'GE NEEDS SVC' : means that the GE unit needs service. Follow the instructions under the Electronics group homepage. You will not see GE data values during this time. You may also see the data 'spike downwards'.
- 'NO PRI MIRR DATA': means that the ACS is not in the correct mode to output data. If the label for 'SECONDARY' is red also, this means that the AUX crate is down.