Posted on 10.04.2012 13:05
Having spend many £££s on a sync cable and borrowed a second dewe-43, I'm about to make my first set of 16 channel measurements using USB instruments. BUT, there is no information in the dewe-43 or the dewesoft 7 manuals about synching two devices. Mostly it's obvious: a) connect both dewe-43s to the pc using usb cables. b) connect the dewe-43s together with the sync cable c) select hardware-setup/analogue Analogue device = DeweSoft USB d) go to the analogue Ch Setup screen and 16 channels are listed (whether you connected the sync cable or not) e) measure as normal but with 16 channels (note that measurement will not start if the sync cable isn't connected) but there are some setup options that are not explained anywhere, dewesoft advice please: In the hardware-setup/analogue screen both the dewe-43s are listed (whether the sync cable is connected or not). By clicking on the Sync column, I can select either dewe-43 to be master and the other is automatically the slave. 1: What difference does it make, which dewe-43 is master? There is another column labelled Setup in which when clicked brings up a dialogue box called "Clock Settings setup" this lets me set a variable called "SR Div" to "OFF" or one of several numbers from "1" to "100". 2: What is the SR Div variable and what difference does it make? I notice that with only one dewe-43 connected, the sync options are now "Master", "Slave", "Standalone" and "Digital Out". 3: What are these additional sync options for?
Posted on 11.04.2012 13:28
Hello Nick, 1: If two DEWE 43's are connected, Master DEWE-43 will provide internal clock for both connected 43's. 2: 'SR Div' in Hardware setup means Sample rate divider of the master clock. (Available on third pin of 'Sync USB' connector.) 3: Meaning of Sync options when one DEWE-43 is connected: - Standalone: Default selection for one connected 43. - Master: Provides clock and trigger if any other device is connected. - Slave: Needs to get clock and trigger from external device. - Digital Out: Use 'Sync USB' on 43 as digital output. See http://www.dewesoft.com/download?file=Instructions_-_Trigger_alarm_on_DEWE_43.pdf - IRIG Master: 43 provides it's own IRIG clock (calculated from PC time). - IRIG Slave: Uses external IRIG clock to sync 43. See http://dewesoft.com/download?file=Instructions_-_Sync_DEWE_43_with_IRIG_B.pdf Best regards, Dewesoft support ( support at dewesoft org ).
Posted on 12.04.2012 16:55
Thanks. Presumably SR Div = 1 is the same as SR Div = Off? I'm not sure why I would need to reduce the Master clock rate, surely the faster the better?
Posted on 13.04.2012 08:41
Nick, SR Div = Off ... no signal. SR Div = 1 ... original sample rate, not reduced. SR Div typically needs to be reduced for devices such as high speed cameras that needs trigger... Best regards, Marjan.