Applies to: Docklight (all versions), Article ID: dl_prb002
This is probably caused by the communication settings or the cable link between your devices.
Check your communication settings first. Are all settings correct (baud rate, parity settings, data bits, stop bits)? If your communication includes a parity bit, all bytes with wrong parity will displayed as a question mark (“?”) in the ASCII communication window.
Test the communication link between the device(s) and the PC next – Do you use the right cable?
If all seems ok, you may also check your PC’s COM ports.
If you have two COM ports available, connect the two ports using a standard null modem cable and then run two Docklight applications in send/receive mode, one for each COM port.
Try sending a “Send Sequence” from the first Docklight application and receive this sequence with the other Docklight application.
NOTE: You may choose to replace the ‘parity error’ question mark by any
other ASCII character. See the Docklight user manual, COM port settings.