I have an Android Xamarin application that prints to a ZD620 Zebra printer using classic bluetooth. There are a couple of questions based on my experience and what I have encountered:
1. If the device makes a call to connect to the printer on thread before the previous print has completed, an attempt to connect to the printer fails and it is not printed.
i.e. I am scanning mulitple barcodes at a time if I rapidly scan 4 barcodes, 1 out of 4 will be printed over bluetooth because the connection is so slow and hangs up the printer as it seems only 1 created thread can connect and print to it at a time.
2. How many devices can be paired and print at the same time as this looks like the issue #1 would grow exponentially given many devices trying to connect over bluetooth and use the same printer.
What are possible solutions that can be implemented for this issue?
What is the normal situation with Printer Spooling given the print is from the device to the printer and "Windows OS" etc are not creating the spooling print jobs?
1 Replies
Hi Mike,
Both Bluetooth (SPP profile) and USB are are essentially serial connections. USB has an advantage in that the connection can be left as always on, where you have to close the connection on Bluetooth at least occasionally or you run into issues with timeouts and battery use.
Given this, we recommend spooling print jobs be handled in a client-server queue architecture. We are working on some documents and sample code to show how to do this better, but I've attached a draft framework. It is just one way to work it, and we know there are others, but this seems to fix most issues. It decouples the UI and slow running print connection so it can happen asynchronously. Hopefully it helps.