Every millisec there is a timer event in the list data stream. It is a 32 bit word containing 0x4000 as high word and as low word for ADC 1 a 1 in bit 0 if it's "alive" i.e. not busy, and a 0 if its busy i.e. "dead", the same for ADC2 in bit 1 and so on.

Busy means that the ADC deadtime signal from the ADC interface is on. Counting the timer word with corresponding bits that are on directly gives the live time in milliseconds for each ADC, counting all the timer words gives the realtime of the run in milliseconds.

Dead time is the percentage of (realtime - livetime)/realtime. Run time is the time of the acquisition measured with the PC clock. At high data rates it is possible that the FIFO gets full and events are lost, also timer events. Then the realtime will be lower than the runtime. Small differences can also arise for example when using a realtime or livetime preset, the acquisition will then stop controlled by the hardware and the software will recognize it a bit later; the "runtime" will therefore a bit larger than the realtime.

True time is the time and date from the PC clock. The Start time and the time when data was written is recorded as a comment with the data. The start time is also shown in the spectrum display window.

The MPA-3 has an optional "Realtime Clock", RTC. It can be used to insert time stamps into the data stream, to use the time like a parameter to acquire dualparameter spectra ADC versus time, and to set a time preset. The RTC is not shown as a counter in MPANT. It is in units of 50 nsec.