ANY-maze Help > I/O devices supported by ANY-maze > The ANY-maze interface device family > The ANY-maze Digital interface > An overview of the ANY-maze Digital interface

An overview of the ANY-maze Digital interface

Introduction

As the name implies, the ANY-maze Digital interface is designed to act as an interface between ANY-maze and a range of 'digital' equipment typically found in behavioural labs. Here the term digital includes devices which have true digital inputs or outputs, for example a TTL input on a shocker, and also equipment which has a digital state (i.e. on/off), such as a lever or an LED.

The Digital interface has six 4-way connectors on its front panel, each of which consists of 2 digital ports, providing 12 ports in total. Each port can be configured to work in one of the following different ways:

Switch input

When configured as a Switch input, a port simply detects when a switch connected to it is opened or closed. For example, an operant chamber may contain a lever that the animal can press - this will typically cause a small switch to be closed. Connecting this switch to a port configured as a switch input would allow ANY-maze to detect the lever presses.

Figure 1. Connecting a lever to an ANY-maze Digital interface is as simple as connecting the two sides of the switch to a switch input port.

Any equipment which is based on a switch (or switches) can be interfaced to ANY-maze in the same way. For example, a 'step-down' platform may hold a switch closed while the animal is on the platform and release the switch (opening it) when the animal steps down - connecting to this switch would allow you to detect when a 'step-down' event occurs. Or a two sided chamber may tilt slightly as the animal walks between the two sides, causing a switch to open and close - connecting to this switch would allow you to determine when the animal moves from one side of the chamber to the other.

You'll find full details about the ANY-maze Digital interface switch input ports, including information on how to connect a switch, here.

TTL input

TTL is a widely used standard digital signal. If you have some equipment which outputs a TTL signal then you can connect it to a port configured as a TTL input and ANY-maze will detect when the signal is high and when it is low.

Full details about the ANY-maze Digital interface TTL input ports can be found here.

Switch Output

A switch output can be used to control any equipment that has is activate and deactivated by setting its input to high or low. They work in the same way as TTL outputs.

Full details about the ANY-maze Digital interface switch output ports can be found here.

TTL Output

A TTL output can be used to control equipment that has a TTL input. For example, some shockers include a TTL 'activate' input, such that when the input is set to a TTL high, a shock is delivered. Connecting this input to an ANY-maze Digital interface port, which has been configured as a TTL Output, would allow ANY-maze to switch the shock on and off. (Note: other shockers have 'remote activate' inputs which need to be connected together to deliver a shock - you can interface to these using the ANY-maze Relay interface).

Figure 2. To control a shocker that has a TTL input, one just has to connect to a TTL output port.

In a similar way, some pellet dispensers use a TTL input to activate the device and dispense a pellet, so connecting this input to a TTL output port would allow ANY-maze to control the dispensing of pellets. (Again, other pellet dispensers require two terminals to be connected together in order to dispense a pellet, and you can interface to these using the ANY-maze Relay interface).

ANY-maze Digital interface TTL outputs can also be used to control LEDs (which make excellent cue lights). In this case the LED simply connects directly to the port, and when the output is set high the LED will switch on.

Finally, another use for a TTL output is to synchronise ANY-maze with another system that includes a TTL input. For example, if you want to synchronise ANY-maze with an electrophysiology recording system, you could connect an ANY-maze Digital interface TTL output port to a TTL input on the electrophysiology system and change the port's state from low to high whenever a test begins. This would provide a simple method to align the data recorded by the two systems.

Incidentally, many optogenetic lasers include a TTL input; this means you could switch the laser on and off using an ANY-maze Digital interface. However, you will usually want to pulse the laser on and off at some set frequency and while the ANY-maze Digital interface can do this, we strongly recommend using the ANY-maze Optogenetics interface instead, as it is specifically designed for this purpose and provides very precise control of the pulse timing (to within 100ns).

Full details about the ANY-maze Digital interface TTL output ports, including how to connect to them and how to use them to generate a synchronisation signal, can be found here.

Photobeam

Photobeams are widely used in behavioural tests for a variety of purposes. For example, a holeboard usually has a photobeam across the holes to detect when the animal 'pokes' - see figure 1. Doors in apparatus sometimes have photobeams across them to detect when the animal moves from one part of the apparatus to another. Corridors sometimes have a series of photobeams along them to detect where in the corridor the animal is, etc.

Figure 3. In this holeboard, when the animal pokes its head into the hole it will break the beam.

When an ANY-maze Digital interface port is configured as a photobeam, it will automatically disable the other port on the same connector. This is because a photobeam requires two ports, one to switch the beam on and off and one to detect the beam at the receiver - therefore you can connect at most 6 photobeams to a single ANY-maze Digital interface.

Photobeams are available specifically for use with the ANY-maze Digital interface, but you can also build your own beams if you wish.

Full details about the ANY-maze Digital interface photobeam ports, including information about the photobeams themselves, can be found here.

Rotary encoder

As the name implies, a rotary encoder detects rotations - specifically rotations of an axle. If this axle has a running wheel mounted on it then a rotary encoder will detect rotations of the wheel; or, if the axle connects to an animal tether, then the encoder will detect rotations of the animal.

Figure 4. An example of a rotary encoder. This could easily be mounted in the wall of a cage and have a running wheel attached to its axle.

We supply a specific rotary encoder for use with the ANY-maze Digital interface, but in fact most incremental encoders (also sometimes called a quadrature or quadratic encoders) can be used.

When an ANY-maze Digital interface port is configured as a rotary encoder, it will automatically disable the other port on the same connector. This is because a rotary encoder requires two ports, as it has two digital outputs; therefore each ANY-maze Digital interface can connect to 6 rotary encoders in total.

Full details about the ANY-maze Digital interface rotary encoder ports, including how to connect a rotary encoder, can be found here.

Photobeam array

Photobeam arrays provide a 'curtain' of photobeams and are often used to detect when an animal rears - see figure 5, below.

Figure 5. When the animal rears it will break the array of photobeams, allowing ANY-maze to detect the rear.

ANY-maze can also use photobeam arrays as movement detectors, which, as the name implies, detect movement of the animal. Movement detectors can't provide the same depth of information about the animal's movements as video tracking, but they can generate reliable movement 'counts' in circumstances in which video tracking can't be used

The ANY-maze Digital interface is only compatible with photobeam arrays designed specifically for it. These are the same arrays as are used by the original AMi device and are available in 40cm and 100cm lengths. Like the individual photobeams, when an ANY-maze Digital interface port is configured as a photobeam array it will automatically disable the other port on the same connector - therefore a maximum of 6 arrays can be connected to a single interface.

Full details about the ANY-maze Digital interface photobeam array ports can be found here.

See also:

© Copyright 2003-2026 Stoelting Co. All rights reserved

ANY-maze help topic T1054