FED3 synchronization with fed3.BNC() and fed3.pulseGenerator() functions

---

Use fed3.BNC(DELAY_MS, loops) to send sync signals from FED3 to a photometry or ephys recording system (or even another FED!) through the BNC output.

How it works

fed3.BNC(DELAY_MS, loops);

Examples:

• fed3.BNC(20, 1) = one 20ms pulse
• fed3.BNC(20, 3) = three 20ms pulses
• fed3.BNC(500, 1) = one 500ms pulse

Two common ways to use it

1. Short pulse trains

Useful for marking different behavioral events. Examples:

• fed3.BNC(50, 1); // 1 pulse means Pellet
• fed3.BNC(50, 2); // 2 pulses means Left poke
• fed3.BNC(50, 3); // 3 pulses mean Right poke

2. Long pulses

Also useful for marking different behavioral events.

• fed3.BNC(50, 1); // 50ms means Pellet
• fed3.BNC(100, 1); // 100ms means Left poke
• fed3.BNC(200, 1); // 200ms means Right poke

---

pulseGenerator()

How it works

fed3.pulseGenerator(pulse_width, frequency, repetitions) to send a pulse train with more precise control over pulse timing than fed3.BNC().

Arguments

• pulse_width: pulse duration in milliseconds
• frequency: pulse frequency in Hz
• repetitions: number of pulses in the train

Example: fed3.pulseGenerator(10, 20, 20);

This sends:

• 10 ms pulses
• at 20 Hz
• for 20 repetitions

---

Notes:

• fed3.BNC() and fed3.pulseGenerator() are blocking because they uses delays internally. This means that no other code will run during the pulses. If you make a 2s pulse, the FED will be unresponsive for 2s while it is making the pulse. Use pulses short enough that they do not interfere with the behavioral task.
• It is a good idea to test everything in your recording setup before assuming it works - improper grounding, inputs, etc, may mean your pulses won't show up as you expect them to.
• It is a good idea to verify you can decode your pulse scheme before doing a billion recordings and learning there's an issue :)