BIN8 TTL Input/Output

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	External equipment connection: SAM Event Synchronisation port and BIN8 unit.

The BIN8 unit connects to the event port, and does not occupy one of the amplifier or stimulator device sockets, so that a SAM may have 2 amplifier/stimulator devices and a BIN8 unit. It allows more convenient connection to the 8 event port TTL lines via 4mm banana sockets, as well as a 25 way D connector which allows direct link up to the printer port of a windows computer. This may be useful where a user stimulus task is programmed on a separate computer, in a computer language or using MEL or ERTS programming systems.


	BIN8 also provides 8 separate TTL outputs and 4 relay closures, which are controlled independently of the 8 event port data lines, greatly expanding capability for external equipment control. The top double row of 4 sockets are the relays, with associated LED on/off indicators, the next row of 8 sockets are TTL output, the lower row of 8 sockets are TTL input, and the bottom row of 4 sockets are two ground and two 5V.


	The 25 way parallel connector is at the front and at the rear there are two 15 way D plugs which link up to the event port of the controlling SAM unit and allow for daisy chain connection via the other 15 way plug to other SAM units in a multiple SAM system.Examples of PSYLAB controlling other devices: buttons and switches for subject response; relay link-up to a solenoid valve to control compressed air puff to elicit blinking in a startle paradigm; link-up of a TTL output to a tachistoscope to trigger its operation.



	SAM event port

Examples of other devices controlling PSYLAB are: connection of a remote button such that the operator or the subject can indicate an event, response or reaction time; link-up to another computer which has been user programmed with a task (e.g. using MEL or ERTS), such that PSYLAB can synchronise with actions in the task (this can be easily done using the task computer’s printer port).

TTL requires a ground wire to be run from the grount terminal of BIN8 to the external device. TTL input is registered as a number between 0 (all low, below 0.4V) and 255 (all high, above 3V).

The SAM 8 bit event connection relates to pins 1 to 8 of the event port, pin 9 is +5V @100mA, pin 10 is ground. It may be used directly by simply connecting up to the 15 way socket, but the safest way to use it is via the BIN8 unit, which provides a safety buffer between external devices and sensitive SAM circuitry, in addition to allowing latched control of relay and TTL outputs.


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		A simple converter is also available to allow direct (buffered) connection to a computer printer port. Pins of the 25 way plug are directly compatible with pinout of the pronter port, so that a straight connecting cable may be used to link the computer with SAM event port.