• RE: Update rate of K2450

    Hi, thanks for response! We have same firmware as you on two out of three units (they all show the same effects)<br> <br> It looks like you have run into exactly the same issue we identified... do you think that this is an intended behaviour of the firmware? (is it a &quot;bug&quot; or a &quot;feature&quot;?)<br> <br> I know that there are transients that can happen when you step voltage on a SMU, particularly under capacitive loading (e.g. the K6430 we have 'rings' for a long time if you load the pre-amp too much with cable capacitance).<br> <br> We need decide ourselves how long to wait for to avoid these effects. Surely 300 milliseconds is a rather conservative estimate for this delay?<br> <br> (Have you plotted the time stamp data on the time axis like the cartoon...this would be the data that really shows how long this delay is)
  • Update rate of K2450

    <p>What is the fastest rate I should be able to sweep/update the voltage output on the K2450, using point-by-point level updates (not a source measure loop controlled by the machine)?&amp;lt;br&amp;gt; &amp;lt;br&amp;gt;</p> <p>I am trying to understand the delay that occurs when the source level is updated, and how this relates to the current measurement range and any automatically applied source delay. I know why delays are added for current&#160;measure (I have seen ringing on high capacitance lines on other instruments when voltage changes) but in this case I just want the fastest source update time.&amp;lt;br&amp;gt; &amp;lt;br&amp;gt;</p> <p>We discovered that sweeps executed point by point could cause a 'pile-up' of voltage updates. You can drop in an *OPC? command to make sure you don't rush the measurement (on another instrument) but the process is slow, hundreds of milliseconds.&amp;lt;br&amp;gt; &amp;lt;br&amp;gt;</p> <p>I tried to set the source delays to zero (:SOUR:VOLT:DEL 0) and confirmed that this deactivated the auto setting :SOUR:VOLT:DEL:AUTO? but this did not help. Changing the current measurement range of the instrument to a less sensitive range changed the delay time by a factor 2, but this did not tally with the numbers in the manual for the autodelay (we see ~ 170 ms for measure range 1uA).&amp;lt;br&amp;gt; &amp;lt;br&amp;gt;</p> <p>This looks like some artificially added software delay that I have not got under control. The response time on other queries is ~normal (10 ms for a range setting query, for instance). Any ideas?</p> <p>PS: I could move the &quot;speed/performance slider&quot; but I assume this has the effect of changing multiple real parameters like the integration time on the ammeter and the delays times and is largely focussed on the noise/resolution of me measurement.&#160;I'd rather set the actual parameters.</p>