Issue / Question
The printer might print duplicate labels whilst the printer is paused such as when reloading labels or ribbon.
Xi4 series, ZM series, 105SL Plus, ZE500
Resolution / Answer
After analyzing the net log, we found the root cause is the PC host not get ACK response for 'ZeroWindowProbe' in time, so host thinks that the connection is lost, then resets it. We know that when the printer sends an ACK response, it will be delayed when printer is in a pause state.
Microsoft support provide the setting of TCP/IP persist timer that send times for 'ZeroWindoProbe' request.
Customers will need to change the registry key as below:
From 0x3 to 0x5
This means that the PC host will send 'ZeroWindowProbe' 5 times. If no ACK response is received after these 5 times, the connection will be reset.
The duration will extend to 9.3 seconds. Printers will then have enough time to send ACK response.