Well, this was embarrassing. It turns outs that a couple a dozen or so of the first DI-155s that we shipped could not make a measurement on analog channel 1. An internal check revealed that all the DI-155s that passed calibration and were sitting in their plastic boxes waiting for labels were fine. Those in their shipping boxes with labels had the channel 1 problem. Hmmm…
It turns out that despite extensive functional tests of the DI-155 before its release, no one bothered to tell the testers that the very last step in the manufacturing process requires that a fully tested, calibrated, and functional DI-155 be connected to a PC that contains a database of all units calibrated to that point. Once connected, the serial number of the DI-155 is read, and a label spit out by a printer to be placed on the underside of the unit’s box. Its been this way with all starter kits since as long as anyone can remember. The problem is that the DI-155’s internal EEPROM is slightly more full with content because of its many ranges and other items, and one crucial location was being erased by the label generation process. You guessed it, the fully tested, calibrated, and validated calibration constants for channel 1 were being replaced with all zeros.The result was a solid, flat line zero response for channel 1 regardless of what you connect to it.
This is old news if your DI-155 has this problem. After the first several customers called with the issue it didn’t take long to discover the cause, and that same day we sent an email to all DI-155 customers informing them of the problem and a pending fix, which was released today.
So, the lesson is just when you think you’ve covered all the bases, look again. There’s probably one you missed. Our apologies to those first DI-155 customers. Your inbox should now contain an email from us describing a fix that can be downloaded from our website, installed, and used to banish this bug forever.