What's digital printing PASS channel?

Digital printing is to print a pattern through inkjet printing machine, but when printing, it is often heard how many PASS channels we choose. What is the meaning of the digital printing PASS number? How does this affect the quality of the pattern?
Digital printing PASS number means
PASS channel is the number of times the nozzle is moved within the unit width. For example, 3PASS is a place to go three times when printing. Therefore, the larger the PASS number, the higher the quality of the picture, but the more time it takes.
The PASS channel is actually the trajectory generated when the nozzle is printed back and forth. If the pass channel is not handled properly, it will easily lead to pattern distortion. When the digital printing prints a pass stripes, there is a malfunction. What are the reasons for the digital cross-printing of the cross-printing strip?
The digital printing machine prints the pass path, which is theoretically unavoidable because the mechanical error cannot be completely eliminated. Digital printing prints the reason for the pass stripes: the print feathering is too low; the bidirectional printing is too fast; the Y-axis belt is loose; the print head is in poor condition; the ink is broken.
Digital printing prints the solution of the pass crossbar:
The appearance of the Pass crossbar is related to the level of printing accuracy. The higher the accuracy is, the smaller the pass path will be, and the less the quality of the print will be affected. Therefore, an important part of avoiding the crossbar is to improve the printing accuracy of the machine.
Digital printing prints the solution of the pass stripes： 
1. The opening of the feathering is to make up for the link between the ink dots in the digital printing machine during the printing process, so that the pattern effect is more natural. You can eliminate the pass crossbar by turning the feathered value at 80 or 100.
2. After the Y-axis belt of the digital printing machine runs for a long time, it will be loose, and you need to tighten the adjustment. If it is driven by a screw, regular lubricant maintenance is required.
3. The digital printing machine must print the test strips before printing every day, and observe the state of the nozzles in time, which is helpful for timely detection of the nozzles and avoiding the appearance of the pass.