From the very first instance of the Videojet print driver, the driver did not report communication errors with the printer as long as communication with an x370 was active.

The driver attempted to configure a two byte response in the printer when a new message was sent but in fact, due to a documentation discrepancy it actually turned off the response it was looking for and turned on status messages that it was not looking for.

In the past few years Rondo noticed that a printer was not even required to make the XL happy, as long as an x370 was connected and communicating. They asked us to add additional checks to detect when the printer failed to respond correctly. However, this was a risky task since we had no printer to test it with. Their initial testing appeared to work on the surface.

We now have a printer simulation from Videojet that allows us to test communication on the PC simulation. Using this, the configuration issue was discovered and corrected so that the response we are looking for will be generated.

The command in question was being sent as [18][01][06][04] when it should have been sent as [1B][01][06][FB]. The last byte is a mask byte and the purpose of each bit to enable or disable a response was backwards. A zero bit enables the response rathers than a one.