The digital tacho channel in a P8000 system offers better time resolution by dividing the main sample period by 16. However it is sometimes difficult to know what level the threshold should be set to so a facility to help you find the optimum level has now been added to the acquisition software.
If your P8000 system has a ‘Tacho’ channel then you can use the automatic threshold detection facility in the single channel setup to find the optimum level to set the for the tacho.
From the single channel setup page select the tacho channel you want to detect the threshold level for from the ‘Name’ drop down list. Then click on the ‘Arm’ button to start the data monitoring of the tacho channel.
When the system is “ARMED” click on the ‘Auto detect tacho threshold’ button (second from right in screen shot below) on the toolbar above the graph display with a typical tacho signal connected to the input.
The software will increment through the voltage range of the tacho channel and will detect an optimum threshold level which falls between the level where the tacho is detected and it is lost again.
When this has been completed the new threshold trigger level will be set in the setup matrix automatically. The user can override this level to fine tune it if necessary.
Once this is complete the display should show a representation of the tacho pulse train generated from the threshold crossings detected.