XLINK 500/100 Operations & Maintenance Manual page # 147
DATA
This is data collected and logged by the station through
measurements. Only logged data may be transmitted. If
Tx Data
Content
is set to
Exclude,
no data from that measurement will be
transmitted.
Like the binary formats, the SHEF format groups all the related data
from one measurement. The data is transmitted in ASCII with sign
and decimal point (if needed). If a data value has not yet been
recorded (or has been erased) the letter M for missing data will be
sent. The most recent data is always sent first. The number of values
sent for each measurement is set on a measurement by
measurement basis.
APPEND
OPTIONS
There are a multitude of optional values that may tacked on at the
end of the transmission. Please see
A
PPEND
O
PTIONS
.
15.6.1.
SHEF Example
Here is a message with three active measurements. Each is set to include two readings. The
random buffer contains the string EXT. This string was given by an external device through the
RS-232 port. Notice how much longer this message is compared to the earlier binary examples.
:HG 3 #15 10.20 10.15 :PC 1 #15 50 49 :TA 0 #15 -22.1 -22.0 :VB 0
12.2
In the example above
:HG 3 #15 10.20 10.15
means that the sensor labeled HG read the value
10.20 three minutes prior to the start of the transmission. It read 10.15 18 minutes before the
start of the transmission, or 15 minutes before it read 10.20. Here is the complete decode:
:HG
Measurement labled HG
3
Reading is 3 minutes old
#15
15 minute measurement interval
10.20
HG sensor reading (most recent)
10.15
HG sensor reading
:PC
Measurement labled PC
1
Reading is 1 minute old
#15
15 minute measurement interval
50
PC sensor reading (most recent)
49
PC sensor reading
:TA
Measurement labled TA
0
Reading is less than one minute old
#15
15 minute measurement interval
-22.1
TA sensor reading (most recent)
-22.0
TA sensor reading
:VB
Battery voltage label
0
Reading is less than one minute old
12.2
Battery voltage reading
SHEFFIX is a modified version of SHEF where the data is positioned in fixed spacing so that it will
line up better when displayed. Each measurement reading is given seven bytes. If a reading uses
fewer bytes, it is padded with spaces. SHEIFIX transmissions are larger than SHEF transmissions.
