Terry Weymouth from UMich figured this out, this is a re-post of his findings.
Request(channelMap, time, duration, mode) Where... recTime is the time stamp on record, lastTime is the greatest time ring buffer for a channel, firstTime is the smallest time in the ring buffer for a channel, maxLastTime is the greatest lastTime over all channels, minFirstTime is the smallest firstTime over all channels (for all duration >= 0 is required) absolute return records for which time <= recTime <= time+duration duration=0 is a special case, returns the single record with recTime <= time newest return records for which lastTime-(time+duration) <= recTime <= lastTime-time; duration = 0 is a special case, returns the single closest record to lastTime-time such that recTime <= lastTime-time oldest return records for which firstTime+time <= recTime <= firstTime+time+duration; duration = 0 is a special case, returns the single closest record to firstTime+time such that firstTime+time <= recTime aligned (e.g. newestAlligned) return records for which maxLastTime-(time+duration) <= recTime <= maxLastTime-time [did you-all ever consider oldestAlligned that is: minFirstTime+time <= recTime <= minFirstTime+time+duration???] after given baseTime is the max of lastTime-duration and time return records such that baseTime <= recTime <= baseTime+duration modified if time < lastTime, compute baseTime is lastTime-duration return records such that baseTime <= recTime <= baseTime+duration if time >= lastTime no data is returned next given that baseTime is the least recTime such that time <= baseTime return records for which baseTime <= recTime <= bastTime+duration previous given that baseTime is the greatest recTime such that baseTime <= time return records for which baseTime-duration <= recTime <= baseTime
'Next' with time < minFirstTime, duration > 0 and 'Previous' with maxLastTime < time, duration >0 both return a list an array of times/data with duplicates in each position but the first and the last
'Previous' with time <= maxListTime and duration = 0
only returned data on channel 0
Comments and more information
See the SAPI page on Request for more information.