The quadrature Timer mode is designed explicitly for use with quadrature encoders. A quadrature encoder is a device that allows you to determine the absolute position of a rotating shaft. It does this by generating two pulses with each part of a rotation (how small of a rotation a "part" is depends on the encoder). One pulse will come before the other if the shaft is rotating in one direction, and the pulse order is flipped if the shaft is rotating in the other direction. The LabJack quadrature timer reads both these pulses and increments or decrements the timer reading depending on which pulse occurs first.
Because it takes two pulse signals coming in on two wires, the quadrature mode requires two timers, even though there is only one reading. The two timers have to be adjacent pairs, with the even timer as quadrature channel A, and the odd timer as quadrature channel B. Reading either timer returns the same, signed 32 bit count, and writing a zero to either timer resets both. Here's some DAQFactory script to initialize the quadrature mode on timers 0 and 1:
AddRequest(ID, LJ_ioPUT_CONFIG, LJ_chNUMBER_TIMERS_ENABLED, 2, 0, 0)
//Configure Timer0 as quadrature.
AddRequest(ID, LJ_ioPUT_TIMER_MODE, 0, LJ_tmQUAD, 0, 0)
//Configure Timer1 as quadrature.
AddRequest(ID, LJ_ioPUT_TIMER_MODE, 1, LJ_tmQUAD, 0, 0)
GoOne(ID)
As you can see, it is one of the easier timers to setup since it doesn't require the internal clock. The easiest way to read the timer is to create a Timer channel: I/O Type is Timer, Channel # is the timer #, in this case 0, Timing can be whatever update interval you would like. Alternatively, you can use LJ_ioGET_TIMER to retrieve the reading from script:
private datain
eGet(ID, LJ_ioGET_TIMER, 0, @datain, 0)
