Simtronics GD1 MK3, Operating Manual

Page: 31 / 76

GD1 Page 31 of 76 850-816926-EN R06
5
On the HART® terminal enter the command:
#AM
Terminal response:
AM
Response on secondary loop (terminal
8) is set to between 3 and 14 mA
depending on the strength of the
optical signal received on the RX.
The system is now entering Alignment Mode (AM). If sufficient initial IR laser light is
collected by the receiver, the mA meter will show a value near 14 mA. If too little laser light
is received at the RX, the meter will show 3 mA. If this is the case, repeat coarse alignment
until the mA meter shows a higher value.
By factory setting, 14mA represent the strongest optical signal received after entering AM.
Any value lower than 14 mA means that the alignment between TX and RX is less optimized
than the best position seen during AM. If the alignment is improved the signal strength is
increasing and the value on the mA-meter will increase. If the signal strength is increased
to above 14 mA, the scale will automatically be increased so the new best position again is
14 mA. By outputting this information it allows for a user to gradually narrow down to an
optimal alignment position by manually sweeping the beam spot back and forth in each
direction.
6
Slightly loosen screw 1 just enough for the
alignment mechanism to be able to move in
the horizontal direction.
7
Align in horizontal direction by turning screw
5. Turn very slowly in the direction whereby
the signal strength increases. The signal
reading will stay close to 14 mA as long as
the signal strength is increasing.
8
When the maximum signal strength is
reached and the mA reading will start to
drop.
9
Turn screw 5 back the other direction until
the signal strength is back at maximum. The
typical signal strength after a successful fine
alignment should preferably be above 13.9
mA. Do not expect to see exactly 14 mA.
10 Tighten screw 1.