How do I set up photogates for data collection?

To answer this question you must know what time interval you plan to measure with the photogate(s).

Each time interval mode has a name. Start with what it is you are trying to measure:

If you need to know how long a gate is blocked by a single object, which you'll then use to find a speed using the ratio of the object length and the blocking time, you'll need "gate timing."

If you need to know the time between successive blocks of one or two gates, you'll need some variant of "pulse timing." For example, projectile motion experiments work best with pulse timing with two gates.

If you need to know timing information from a pulley or a picket fence object, you'll need "motion timing."

If you need to measure the period of a pendulum, which is the time from the first to the third block of a photogate, you need "pendulum timing."

There are also other, less common timing modes.

The default timing mode is motion timing, which is perfect for measuring g with the Picket Fence, order code PF, $7, for more information, see TIL 2311: How can I use a Vernier Photogate to measure g?.

If you need to use a different photogate mode, you can set up the interface to perform the appropriate data collection.

Using Logger Pro 3:
The easiest thing to do is to use a prepared experiment file that comes with Logger Pro 3.
1. Choose File / Open
2. Navigate to the folder Experiment Files/Probes and Sensors/Photogates.
3. The files in this folder handle most common photogate timing situations. See below for additional definitions of terms used in Logger Pro 3 experiment files.

Using LabQuest as standalone:
1. Tap the Mode box or choose Data Collection from the Sensors menu.
2. Choose the appropriate mode from the drop-down menu.
3. Set the requested variables to match the experiment, such as the length of the object or the distance between gates. This is used for calculating velocity and acceleration data.
4. Select OK.

Here is a complete list of the terms used in Logger Pro 3 experiment files:
"Gate" timing means timing how long a photogate is blocked.
"Pulse" timing means timing from the blocking of a photogate until the next blocking of a photogate.
"Motion Timer" means timing from leading edge to leading edge of a picket fence like object (object with a series of opaque bars, evenly spaced)
"Bounce" timing is meant for studying the bounce of a ball using a photogate mounted one ball diameter above the floor.
"Flash" timing measures how long a photogate is unblocked. It can be used to measure how long a camera shutter is open.
"Strobe" timing measures the time between unblocking events of the photogate. It can be used to check the timing of a strobe light, if the light replaces the IR source of the photogate.
"Collision" timing is like gate timing, but assumes two photogates are used to measure speeds before and after a collision. The moving objects are assumed to have "flags" of known length on them that go through the photogates.
"Pulley" timing assumes you have a Smart Pulley or a Super Pulley mounted so that it blocks the photogate with its spokes as it turns.
"Pendulum" timing measures the period of a pendulum if mounted at the bottom of the swing.
"Jump" is set up to use with a laser beam along the floor pointed into one of our newer photogates which allows you to use the laser beam as the photogate beam. It measures the hang time of someone jumping.

Note: For data collection with TI devices, see: http://www.vernier.com/calc/index.html