When the speed measured by the two encoders is not the same, the higher speed value is used as a reference for this
calculation.
Encoder 1/2 [p/cm]
—Encoder (1 and 2) pulse number per centimeter. For both encoders, the minimum value is 50 (default)
and the maximum value is 1000. This is based on the number of pulses the encoder supplies per revolution and on the ratio
between the vehicle wheel and the friction wheel on which the encoder is mounted.
Figure 55. Friction wheel and vehicle wheel
Friction Wheel
Vehicle Wheel
To calculate Encoder 1/2 [p/cm], follow this example:
•
The vehicle wheel has a diameter of 40 cm.
•
The friction wheel on which the encoder is mounted has a diameter of 4 cm.
•
The incremental encoder supplies 1000 pulses per revolution.
The circumference of the vehicle wheel is 40 cm × π = 125.66 cm.
One revolution of the vehicle wheel corresponds to 10 revolutions of the friction wheel, and therefore the encoder supplies
10,000 pulses per revolution of the vehicle wheel.
To calculate the Encoder Ratio (EncR) (the number of pulses per centimeter of distance covered by the vehicle), use the
following formula:
EncR = P
rev
÷ C where
P
rev
= pulses per revolution of the vehicle wheel
C = circumference of the vehicle wheel
In this example, the EncR value is 10,000 pulses ÷ 125.66 cm = 79.58 p/cm. In the configuration software, enter the rounded
value of 80 p/cm in the relevant
Encoder [p/cm]
field. The software calculates the maximum allowed speed based on this
data.
After setting the encoder values, configure the Zone Set switching. This parameter group allows editing the Area Switch input
configuration depending on the number of selected Zone Sets and the Speed Range of each Zone Set.
Area Switch inputs select Zone Sets
—If a different input switch coding is configured with the Area Switch inputs, the
relevant Zone Sets will have either overlapping or different Speed Ranges. In this case, all Area Switches must differ by two
input bit states to be valid.
Combination of Area Switch inputs and Encoder Speed range select Zone Sets
—On the other hand, if more Area
Switches share the same input switch coding, configure different Speed Ranges for each Zone Set.
To set Valid Speed Ranges for each Zone Set, the user first needs to calculate the maximum and minimum speeds that the
scanner can read. To calculate the maximum speed (V
max
), use the following formula:
SX Safety Laser Scanner
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