Instruction manual

14
3.2. Connecting the HPV unit to the data logger:
There are two leads which must to be connected to the HPV unit - a signal lead and a
power lead. The pin-out of these leads is listed below.
Signal lead: This lead has 7 coloured wires which must be connected as follows:
orange = 1H or 3H or 5H (analog input)
orange/white = 1L or 3L or 5L
blue = 2H or 4H or 6H
blue/white = 2L or 4L or 6L
green = AG (analog ground)
green/white = C1 or C2 or C3 (control line)
white = AG or GND (cable shield)
Power lead: This lead has 2 coloured wires which must be connected as follows:
black = GRND
red = +12V
IMPORTANT:
The black and red wires go to the POWER on the heat-pulse unit. A
separate battery should be used for the logger. ALWAYS connect the red wire first, to
avoid shorting out the logger. Also, be careful that you don’t plug the wrong cable into
the heat-pulse unit, since this may short-out the HPV unit or the logger (It hasn’t
happened yet, but that’s little consolation for when it does!!!). As a precaution, there is a
diode inside the heat-pulse unit to protect it against reverse-polarity.
VERY IMPORTANT:
If the same battery powers the logger and the heat-pulse unit then
do not connect the green wire of the signal lead to AG. This would cause a ground loop
and might affect the results...