Installation
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2019 – Valeport Ltd
3.2.2.
Digital Current Loop
In Direct Reading Mode, where cable lengths are in excess of 50m, it will be necessary to communicate via
Digital Current Loop. This is done automatically by the Model 8008 Surface Unit, but if operation is via PC a
Digital Current Loop adapter will be required. The unit requires 12-24V DC external power, and takes
approximately 120 mA. Connection is via the Deck Lead to the main signal cable, and via data interface lead)
to the RS232 communications port on the PC. A variety of power cables are offered as options.
3.3.
Serial Data Format
The serial data format as transmitted from the 106 depends on the parameters fitted.
The serial data string below shows the data string for a 106 with all parameters fitted. If temperature and
pressure are not fitted, only speed and direction are available. The data string is fixed width and padded with
zeros as required - there is no delimiter.
S = s.sssD = ddd.ddP = sppp.pppT = tt.ttt<CR><LF>
Where:
S denotes Speed
D denotes Direction
P denotes Pressure
T denotes Temperature
s.sss
= Speed reading
ddd.dd
= Flow heading
sppp.ppp = Pressure reading where s is the sign
tt.ttt
= Temperature reading
3.4.
Batteries
The internal battery contains one D cell (either alkaline or Lithium), which has a capacity of 10.5 Ah if a high-
grade cell is used. The overall current consumption of the unit depends on the sampling set up. Typical
battery life figures are shown below.
When power is taken from the internal battery (1.5V alkaline D cell), battery life is approximately 30 days at
10 second sampling rate, or 56 days at 5-minute sample rate.
Using a 3.6V Lithium D cell, life is approximately 90 days at 10-second sample rate, or 180 days at 5-minute
sample rate.
To aid the user in determining how much battery life remains, the battery voltage is displayed in DataLog x2.
3.4.1.
8008 - CDU
The 8008 contains 8 "C" cells, giving an operating lifetime for the batteries in excess of 40 hours continuous
use. The CDU will operate on a 12vDC external DC supply. See Section 5.2 for details of how to change the
batteries.
3.4.2.