If I mark up a label on my media roll in my printer so it will cause a non-readable bar code, the verifier will stop the printer one label after the bad label. Why doesn’t it stop on the bad label?
This is typical of the interface kits when printing batches of labels. It is a system timing issue. When a label is marked up, this causes a No Read condition. No read conditions are detected by using a sync input to the SV unit. The SV unit is programmed to expect the number of bar codes to be analyzed during the sync interval (in the case of thermal printers the number of codes on the label.) In most interfaces for thermal printers, the start of the next label being printed essentially ends the sync period (and starts the next period). Therefore, the SV unit cannot send the “stop” signal to the printer until the next label has begun to print, resulting in the situation where the printer stops one label late. NOTE: In many SV output modes used in printer interfaces, an output for a code that has been decoded, but analyzed for poor quality, is sent as soon as the code exits the beam. In this case that “stop” signal is sent to the printer before the next label is started, therefore the
