MULTI-THREADED CLIENT/SERVER technology for robust
deterministic real-time acquisition of
data
The SERVER
acquires and parses the raw data, captures it to hard disk
with optional checksum and time-stamp, and communicates
with clients, locally or over a network.
The CLIENT
communicates with the server (locally or via network),
receives and verifies data sent from the server,
post-processes it for scaling or conversion, displays the
data and (except for the browser client,) stores it to
local disk.
Special emphasis
on providing a variety of tools to facilitate extracting
individual data items from large mixed blocks of incoming
data.
Many data
channels can share input or interrogate for input all from
a single port. For example, this is useful for large RS-485
serial loops having many different sensors
connected.
Data channels
can be "attached" to other data channels. That means they
see what the parent channel sees and so can further extract
subsets of data from the parent channel. Another channel
can in-turn "attach" to that one and so on for as many
different subset data channels as desired.
Optional date
and time stamp and data checksum.
Browser based
real-time monitoring of the data from anywhere having
Internet connectivity. Data may be displayed in a variety
of eye-pleasing ways including gauges, stripcharts or
digital or alphanumeric text displays.
Incoming data to
be monitored may be filtered through a transfer function so
that raw sensor data can be displayed with whatever scaling
is appropriate for the sensor, including expanded
sub-ranges.
Local or remote
over network logging of acquired data to hard
disk.
Written entirely
in the Java programming language for maximum flexibility
and reliablility.
CH 3: SERVER AREA
TEMPERATURE.
CH 4: SERVER ROOM AIR COND.
OUTPUT.
CH 5: OUTSIDE
TEMPERATURE.
SENSOR: OMEGA junction type "T"
Thermocouples. Accuracy +/- 1 degree F.
30 second data
point.
CH 7: STATION PRESSURE
(Mb).
SENSOR: Setra model 276
Barometric Pressure Transducer. Accuracy +/- 0.10% FS
(1100Mb)
900 second (15 minute) data
point.
CH 8: PREMISES CURRENT -
AMPS.
SENSOR: Triplett current probe.
Accuracy 1% FS.
30 second data
point.
CH 9: TEMPERATURE - DEGREES
F.
CH 10: RELATIVE HUMIDITY IN
%.
SENSOR: RM Young model 41372LC
Relative Humidity/Temperature Probe. Accuracy RH 3%, TEMP
+/- 0.54 degree F.
900 second (15 minute) data
point.
CH11: REMOTE TOWER ELECTRONICS
BOX TEMPERATURE.
SENSOR: Temperature Probe
(semiconductor junction). Accuracy +/- 1 degree
F.
30 second data
point.
CH12: PRECIPITATION -
Millimeters (MM).
SENSOR: RM Young model 50202
Heated Precipitation Gauge. Accuracy +/- 1 MM (+/- .04
inch)
COLLECTION CHAMBER auto-empties
at 50 MM (0.197 inch) of precipitation.
600 second (10 minute) data
point.
Channel 3 through 12 sensors
are acquired via precision DGH Corporation
acquisition modules. These modules include input
signal conditioning, 16 bit A-D conversion (including the
sign bit) for 15-bit, 32000 count +/- full-scale
resolution, scaling of data to engineering units, optional
digital data filtering, optional programmable transfer
function and serial output circuitry.
Each module interfaces to the
MainDAS(tm) via an RS-485 data bus.
Modules are as
follows:
Channels 3, 4 and 5 utilize a DGH
model 5332 with four channels of "T" Thermocouple input.
Accuracy +/- 1 degree.
Channels 7, 8, 11 and 12 utilize a
DGH model D5132 with four channels of 0-5 VDC input.
Accuracy +/- 0.02% of full-scale.
Channels 9 and 10 utilize a DGH
model D5252 with four channels of 4-20 MA input. Accuracy
0.04% full-scale.
