If an entry product (tracked part) moves backwards, the tracking length signal decreases. However, the internally filtered length signal in ibaQDR does not decrease; it remains at the last maximum value. When the entry product starts moving forwards again, the tracking length signal increases again. When the tracking length signal is greater than its previous maximum, the internally filtered length signal in ibaQDR also starts to increase.
Measured length value (blue), filtered length signal (red) and length values used (green)
It is possible that an entry product is moved backwards and a piece of it is cut off. The entry product length at the change of ID is then shorter than the previous maximum length. ibaQDR detects this and the measured values for the missing length sections are removed. In the following example, the entry product was 60 m long. It was then moved back 20 m and cut. A new entry product with tracking ID (coil ID) 2 is then welded on. ibaQDR now has an entry product with ID 1 and a length of 40 m.
Entry product ID (blue), measured length value (red) and length values used (green); note: The right-hand green line belongs to the next entry product with ID 2.
Moving back can be more complicated if an entry product is completely discharged from the line. The following example shows this situation.
Entry product ID (blue), measured length value (red) and length values used (green)
Entry product 2 moves into the line and moves 30 m. It is then moved back. The file for entry product 2 is closed at this point. The total length of entry product 2 is 0, as it has been completely discharged. Entry product whose length is less than MinEntrycoilLength (default = 5 m) are removed from ibaQDR. The entry product file for ID 2 is therefore removed. The line continues running, which means that ID 1 appears at this measuring point again. It begins at its final length of 140 m and then reverts to 120 m. ID 1 then advances back to 140 m. The filtered length for ID 1 is then 0 m. Therefore, this entry product file is also removed. ID 2 then moves back into the line. A new entry product file is generated and this is used. This section is shown in green in the illustration. There is also another situation that can occur.
Entry product ID (blue), measured length value (red) and length values used (green)
Entry product 2 moves into the line and is completely discharged. Entry product 1 is moved back 20 m and then cut. Entry product 2 moves in again. ibaQDR has removed the first file for entry product 2 and the second file for entry product 1. ibaQDR has also detected that entry product 1 has been cut, i.e. it will remove 20 m from the first file for entry product 1. The green sections in the figure show the data used for entry products 1 and 2. The value for MinEntrycoilLength can be specified in the dialog box for configuring the data store:
