Radial Maze TTL Interface
16 events · simple 6-byte · single BNC
Overview
The Radial Maze TTL interface provides 16 distinct event signals corresponding to paired infrared sensors on each of the 8 radial arms. Two sensors per arm (entry and end) give your recording system precise spatial resolution for place cell and spatial memory studies.
Each sensor crossing is encoded as an ASCII letter (A through P) in a 6-byte serial frame. With 8 arms and 2 sensors each, you can reconstruct the complete arm-visit sequence and dwell times from your electrophysiology or imaging timeline.
TTL Event Map
simple protocol6-byte frame115200 baud10ms resolution
| Event | Code | Sensor | Description |
|---|---|---|---|
| IR010 | A | Arm 1 entry | Animal enters arm 1 |
| IR011 | B | Arm 1 end | Animal reaches end of arm 1 |
| IR020 | C | Arm 2 entry | Animal enters arm 2 |
| IR021 | D | Arm 2 end | Animal reaches end of arm 2 |
| IR030 | E | Arm 3 entry | Animal enters arm 3 |
| IR031 | F | Arm 3 end | Animal reaches end of arm 3 |
| IR040 | G | Arm 4 entry | Animal enters arm 4 |
| IR041 | H | Arm 4 end | Animal reaches end of arm 4 |
| IR050 | I | Arm 5 entry | Animal enters arm 5 |
| IR051 | J | Arm 5 end | Animal reaches end of arm 5 |
| IR060 | K | Arm 6 entry | Animal enters arm 6 |
| IR061 | L | Arm 6 end | Animal reaches end of arm 6 |
| IR070 | M | Arm 7 entry | Animal enters arm 7 |
| IR071 | N | Arm 7 end | Animal reaches end of arm 7 |
| IR080 | O | Arm 8 entry | Animal enters arm 8 |
| IR081 | P | Arm 8 end | Animal reaches end of arm 8 |
Setup Instructions
- Connect the TTL module to your computer via USB. Note the COM port in Device Manager.
- In ConductMaze, go to Settings > TTL and select the COM port. Set baud rate to 115200.
- Connect a BNC cable from the TTL module to your recording system digital input.
- Set pulse duration based on your recording system sample rate (default: 1000ms).
- Click "Test Pulse" to verify signal detection on the recording system.
- Run a test session and manually trigger each arm sensor to confirm all 16 events register.
Common Pitfalls
- ⚠With 16 sensors, rapid arm transitions can queue multiple TTL events. The 50ms inter-frame delay serializes them, but typical arm-visit durations (2-5 seconds) prevent collisions.
- ⚠IR sensor alignment is critical — if a beam is partially blocked by bedding, phantom triggers will appear in both behavioral and electrophysiology data.
- ⚠Ensure your recording software can distinguish events by pulse timing, since all 16 events share the same BNC channel. Alternatively, log events in ConductMaze and align post-hoc by timestamp.
Methods Text (Copy-Paste)
Spatial navigation was synchronized with neural recordings using the ConductMaze TTL module (ConductScience, Skokie, IL). The module encoded 16 radial maze IR sensor events (entry and end sensors for each of 8 arms) as 6-byte serial frames transmitted at 115,200 baud with 10ms resolution. TTL output was delivered via BNC to the recording system digital input for offline alignment of place cell activity with arm-visit sequences.
Suggested text for the Methods section of your manuscript.
Compatible Products
ME-OC-TTL
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