Sequential / Overlapped Commands; Query Response Timing - Newport LDC-3706 Series User Manual

Sequential / Overlapped Commands

All device-dependent commands are executed in an overlapped manner: subsequent commands
may begin before the current command has completed. Some common commands are sequential;
the next command must wait until this command has completed. The operation complete flag is set
after the conditions outlined in the Operation Complete Definition have been satisfied.
The *WAI (common command) is an example of a sequential command which forces the next
command to wait until the no-operation flag is true. This is essentially the same as waiting for the
OPC flag to become true, because the no-operations-pending flag is used to set the OPC flag (bit 0
of the Standard Event Status Register).
Commands which change the status of the instrument limits, or change its mode, or status enable
registers, will not have their OPC flag set until all current writing to non-volatile memory has been
completed. This ensures the OPC flag is never set prematurely.

Query Response Timing

Query responses are evaluated at the time the query request is parsed, and not at the time the
response message is sent. In most cases, this does not create a problem since the time between
parsing a query and sending its response is small.
December 2019 51 LDC-3706 Series Laser Controller