2
0
2
0
-1
1
50
Operation and communication
5.2
Operation Using Control Codes
In numerous positioning system applications, defined processes (= event) must be started at
specific positions. This means that the exact positions must be defined via code tapes for posi-
tioning.
If an event needs to start at a particular position or a direction decision needs to be made, a
control code is mounted parallel to the actual lane.
Only a specific event and the associated process then have to be programmed into the plant
control system. The position in which the corresponding control code is placed next to the code
tape for positioning does not have to be determined until the point of final commissioning of the
plant. Even if subsequent changes are made to the layout of a plant, the relevant control code
is simply moved to the new position without the need for program modifications.
Control codes are short code tapes measuring one meter in length. The control code has an
encrypted number. Control codes have numbers ranging from 001 to 999.
When the read head enters the range of a control code, it sets the control code flag in its output
data.
The 1-meter-long control code can be shortened. However, the minimum length should be 3
codes (60 mm). If the speed of the read head increases, a longer control code is required. If the
read head travels at maximum speed, a full-length control code of 1 meter must be positioned
next to the code tape for positioning.
The minimum length of a control code can be calculated according to the following formula
depending on the travel speed and trigger period:
L
control code
= 60 mm + V
max
[m/s] * T
Trigger
[s] x 2
The trigger period is 40 ms.
Control codes are identified by the printed number, in this case "Control 12".
Figure 5.3
PGV-CC25-0012
The illustration shows part of control code #12
Refer to the "Accessories" chapter for ordering information relating to control codes.
Example
Example calculation
The minimum length of the control code at a speed of 3 m/s and a trigger period of 40 ms is:
L
Event marker
= 60 mm + 3 m/s * 40 ms * 2 =
300 mm
