Manual Chapter 5

6-25
Dual Pass
Dual Pass functions similar to the Auto Sweep mode except data is automat-
ically acquired as each laser head passes by each other. This mode, like
Manual Sweep, is useful for performing uncoupled or non-rotational align-
ments. In this mode of operation, PSD and angle data are only taken when
the laser beam of each laser head enters the “valid data” window centered
on the vertical centerline of the other head’s PSD.
Note
With the Dual Pass method, a special cable is required to syn-
chronize the two Laser Heads since they will be moved inde-
pendently of each other and will not always be in alignment
with each other. When using direct connect communication,
the Model 821510 direct connect cable is connected between
the laser heads and analyzer to synchronize the laser heads
while using the Dual Pass method. When using RF communi-
cation, the Model 8215C2-PM “Dual Pass” cable is connected
between the two laser heads to synchronize the laser heads
while using the Dual Pass method. For longer spans the Model
800002 and Model 800003 extension cables can be added
between the Model 821510 direct connect cable/Model
8215C2-PM “Dual Pass” cable and the laser heads.
Two ways of hooking up the laser heads for Dual Pass. Direct Connect (left) and RF
Communication (right).