iCon Behavioral Control Interface

The iCon is a behavioral control interface designed to support easy or complex behavioral experiments. It has interchangeable analog and digital modules to fit the needs of any experimental paradigm. It can control most third-party behavioral chambers. The iCon connects directly to any TDT RZ processor with a DSP-M or optical quad DSP card and is controlled with TDT's Synapse software — resulting in high-bandwidth, precision control of behavioral hardware with real-time signal monitoring and full integration with neural recordings.
The iCon is available with two (iCon2) or four (iCon4) module slots. It is configurable with the following modules:
- iH10 High Voltage Interface
- iM10 Multi-function Interface
- iL24 Digital Logic Interface
- iR5 IR Driver Interface
Physical Setup
The iCon connects to a DSP-M or optical QZDSP card in your RZ processor.
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Single iCon connected to a DSPM card in an RZ5D |
You can connect multiple iCons to the same DSP interface card.
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Two iCons connected to a single DSPM card in an RZ5D |
Features
Power
The iCon is powered by an integrated switched-mode power supply. The power supply auto-detects your region’s voltage setting and no further configuration is needed. The power switch is located on the back panel.
Status Light
The iCon front panel display Status light reports system connection information.
I/O Control
At the most basic the TDT iCon system can replace existing devices such as the Med Associates, Colburn or Lafayette systems that interface to a standard operant or behavioral box with input and output lines, where the output lines drive feeders, lick meters and other devices that require more than a digital trigger. At the more complex level the TDT system can be used to send and receive complex signals to control multiple hardware devices.
Replicating an Existing Behavioral Control System
The TDT system provides a unifying interface for sending and receiving behavioral information from a behavioral control box without the need for the external devices from these other companies.
iCon Control
The iCon can be controlled in the following ways:
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Bi-directional real-time communication between the iCon and an RZ processor, running in Synapse.
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Client software using the SynapseAPI to control the iCon outputs through Synapse.
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Pynapse Python Coding Gizmo in Synapse controlling the iCon outputs and managing full behavioral state control.
The iCon object in Synapse lets you configure how the iCon modules are controlled (either through real-time signals on the RZ itself, client-controlled via the SynapseAPI, or directly integrated in a Pynapse gizmo) and how to route iCon input state changes for storage or further closed-loop processing.
Modules
iH10 High Voltage Interface

The iH10 features 10 bidirectional interface ports to provide direct control of high-voltage (e.g. 28V signal) cage elements including Med Associates and Lafayette.
- The ports are configurable in Synapse as either inputs or outputs
- Manual trigger buttons simplify testing and debugging of connected behavioral components
- Status lights make it easy to monitor component activity during sessions
The 'O' LED lights when the port is driven by Synapse, and the 'I' LED lights when the port is driven by Synapse, by an external device, or by the manual button press.
The iH10 uses 1.57 mm diameter standard Molex pin and socket connectors. An output port can source up to 1 A maximum. The maximum total output per iH10 is 1 A. The maximum total output per iCon is 3 A.
For information on software control of the iH10, see the Synapse Manual.
iH10 Pinout
As an Input, the Signal line floats to +28 V. Short the Signal line to ground to trigger it. As an Output, the Signal line floats by default and is shorted to 0 V when triggered.
iM10 Multi-Function Interface

The iM10 has multiple specialized I/O functions, including advanced audio processing for auditory behavioral experiments.
- Drive a speaker (e.g. MF1) directly up to 4 W via an RCA connection.
- Record cage sounds via an embedded microphone amplifier.
- Connect with many common cage elements (e.g. touch sensors) via BNC ADC inputs and DAC outputs.
- Streamline setup with a range of embedded signal processing options.
The iM10 analog input / output range is ± 5 V. The onboard analog processing runs at 800 kHz, independent of the RZ sampling rate.
For information on software control of the iM10 and all of its available features, see the Synapse Manual.
Inputs
The iM10 has four analog inputs. Inputs 1 and 2 have a 50 kOhm input impedance and feature an optional microphone amplifier with 40 dB, 50 dB, or 60 dB gain and attack/release ratios of 1:500, 1:2000, 1:4000. When using the microphone amp input, note that the input signals are inverted.
Important
Do not connect anything to the BNC Inputs 1 and 2 when the microphone amp is enabled.
Inputs 3 and 4 have a 10 kOhm input impedance by default with optional adjustable input impedance and bias voltage. Options are:
- 10 kOhm to Ground
- 1 kOhm (+5 V positive bias)
- 50 kOhm (+5 V positive bias)
- infinite input impedance
The inverting input (BNC shell) can either be tied to Ground or a -5 V negative bias.
Add up to 60 dB gain to the signal on each individual input.
Each Input has two LEDs. The top LED is a clip light that flashes if the input signal is >~ 4.75 V. The bottom LED is a signal LED that will light when that processed input triggers.
Touch Inputs
The iM10 has two touch sensor inputs. These have an independent ground. They use a 750 nA current and trigger if the measured impedance between the input and ground is <= 10 MOhm.
Outputs
The iM10 has four analog outputs. The outputs have a 10 Ohm output impedance. Output a pre-programmed set of waveforms (DC Voltage, Tone, White Noise, Pink Noise, Square, Clock, or PWM), or a user-defined waveform. See the Synapse Manual for the full list of options.
Outputs 1 and 2 are paired. This means the choice of waveform shape for Output 2 can be limited depending on the selected waveform for Output 1. Also, the signals generated by Output 1 and Output 2 can be mixed to play out a single speaker.
Likewise, Outputs 3 and 4 are also paired.
The iM10-generated waveforms use a ± 5 V amplitude. Apply up to 50 dB attenuation to each individual output, adjustable at run-time.
Each Output has two LEDs. The top LED is a clip light that flashes if the output signal is >= 4.9 V. The bottom LED is a signal LED that will light when that output is enabled.
The RCA connectors can directly drive speakers. These connectors are driven differentially to give more power out. The RCA connectors should only be connected to speakers. If you are controlling an external amplifier then use the BNC outputs.
iL24 Digital Logic Interface

The iL24 module can communicate with external behavioral components using 24 bits of 5 V or 3.3 V TTL logic signals.
- There are four bit-wise inputs and four bit-wise outputs available with BNC connectors and status light for each
- The DB25 connector has access to all 24 addressable bits
- Two rows of 8 status LEDs on the front panel show the state of the word input and output bits
- The front panel switch toggles between +3.3 V and +5 V logic for all 24 bits of I/O on the iL24
- Each bit can source up to 6 mA maximum current
For information on software control of the iL24, see the Synapse Manual.
DB25 Pinout
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iL24 pinout, looking into the connector |
iR5 IR Driver Interface

The iR5 is a specialized interface for up to five infrared sensor beams. This module has built-in power and logical connections to drive external IR sensors and sends TTL events whenever the subject crosses the beam, without the need for any external signal processing.
- Manual trigger buttons for each IR port simplify testing and debugging
- Status lights for each IR beam monitor subject movement during sessions.
For information on software control of the iR5, see the Synapse Manual.
Output Power
The IR LED output power is adjustable through Synapse software configuration (1-8). This adjusts an in-line resistor value from 4 kOhm to 500 Ohm. Power output depends on this power setting and the voltage drop of the LED. The table below shows the supply current for a typical IR LED with a 1.4 V voltage drop.
Sensor Input
The sensor power output has a 10 ohm resistor in line. The output voltage changes with the current draw as follows:
iR5 Pinout
When the Sensor output is pulled low, it triggers the event.