AT BF5, User Manual, Page: 21 / 50

BF5 User Manual v 2.3 Use with a data logger  21
Analogue outputs
Connect the BF5 to a data logger via the 8-pole M12 waterproof connector
using cable type
SP-BF/w-05 .
See also Cables on page 11.
Additional weatherproof extension cables with M12 connectors at each
end are also available (type
EXT/8w-x where x = 5, 10 or 25m).
BF5 analogue output connector pin-out
(looking into the cable at M12 connector end)
Signal
Name Pin
No
SP-BF/w-
05 Cable
Cable Notes
Total 1 ---- White Total output
Diffuse 2 ---- Brown Diffuse output
SigGND 3 ---- Green
Signal ground (connected to DL-Gnd
internally)
Sun 4 ---- Yellow Contact closure on sunshine
DL-Gnd 5 ---- Grey Datalogger power ground
DL-Power 6 ---- Pink Datalogger power supply 5 - 15V 2mA
Htr- 7 ---- Blue Heater ground
Htr+ 8 ---- Red Heater power supply, 12V 1.5A max
Screen Screen Cable screen and BF5 ground plane
The Total, Diffuse and Sun outputs are active 100ms after a voltage is
applied to the data logger power cable, and then updated every 250ms.
The Total and Diffuse outputs have a range of 0V – 2.5V, with an internal
resistance of 100

. There is also some protection on these outputs if they
are taken outside their normal range. These outputs should be measured
by a high impedance voltage input channel, with SigGND taken to the
negative input of the channel.
The sun output is switched by a FET (transistor) to ground. When there is
no sun, this output is open-circuit. When there is sun, it is connected to
ground. Any voltage applied to this output should be between 0V and 15V,
with a maximum current capacity of 500mA (0.5A). If this output is used to
switch more than a few milliamps, you should ensure that the current
flows back through the DL-Gnd cable, and not the SigGND, otherwise
there may be voltage errors in the Total and Diffuse measurements.
The DL-Power and DL-Ground connections provide power to the sensor
circuitry (but not the heater), and enable the analogue output signals.