OK, will keep trying. Signed 4 byte number, maximum value of 65535. I may try unsigned 2 byte number as well then. I'm slightly surprised that setting the number of samples is not done by a SetOption() command. After all, there is a GetOption(I1_NUMBER_OF_AVAILABLE_SAMPLES) (which they say is read only). Is "2009" the same as " "IntegrationTime"? Right. Time for some experiments. Regards, Bill -----Original Message----- From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx] On Behalf Of Graeme Gill Sent: Wednesday, 04 April 2012 09:20 To: argyllcms@xxxxxxxxxxxxx Subject: [argyllcms] Re: i1 [EyeOne] USB Command Set Bill Davy wrote: > You suggest I1_TriggerCountedScan() will take a number of samples > (...) samples to take. But what is the argument type likely to be? > There seems to be a taste for using a char* string which seems a bit > arcane but is flexible and universal (well, almost, as we seem to > ignore MBC/UTF/Unicode/wchar issues). I tried DependencyChecker to > see if it reveals the argument list which for some reason I thought > was embedded (albeit "decorated"), but it did not. I'd imagine it is a 32 bit signed int, with a maximum value of 65535. I understand that you can get the current sample time for a particular mode using I1_GetOption("2009") [Should be around "0.010" for Rev A, and about half that for Rev B or Rev D), and the total measurement time should be be that number times the I1_TriggerCountedScan() parameter. > I guess I shall just have to try and see how it crashes! There is an > internal function _sipSetNumPeriodsToMeasure() which I think takes a 4 > byte integer (if I undecorated it correctly). I think sip* is for a different instrument (one of the Sequel Chroma colorimeters ?). Graeme Gill.