Answer: The IP340 has two 8-channel banks. If you are setting timers for sampling at a desired rate and are getting a different rate or getting poor data, you may need to check your timer settings.
There are two timers to set, the "Conversion Timer" and the "High Bank Timer."
The Conversion Timer determines how often the Low Bank (Bank0) of channels is sampled. If you set it for 20µS (A0Hex), then Bank0 will be sampled every 20µS. It should never be set less than 8µS (40Hex) if you are sampling only the low Bank0. If you are sampling the high bank (Bank1) as well, then you must always be 8µS (40Hex) greater than the value stored in the "High Bank Timer." This allows the necessary time for the High Bank to convert before starting the next Low Bank conversion.
Conversion Timer Value > (8µS(40Hex) + High Bank Timer Value)
(Conversion Timer Value +1) / 8,000,000Hz = T (seconds)
The High Bank Timer is the time measured from the start of Bank0 conversions to the start of Bank1 conversions. To leave time for Bank0 to complete, the minimum value for the High Bank Timer is 8µS (3FHex).
High Bank Timer > 40Hex (8µs)
(High Bank Timer +1) / 8,000,000Hz = T (seconds)
By following these simple rules, you should be able to set the timers to your desired settings.