Technical descriptions and block diagrams

Electrode connections
Electrodes connect to a probe on a ~1 meter shielded cable that carries the signal to the headstage HS4, four channel headstage, which amplifies and digitizes signals using high performance instrumentation amplifiers and special high resolution A/D converters. The HS4 is connected to the DB4 controller/receiver in XBUS via a noise immune optical fibers offering optically isolated loss-less communication. Digital Signal Processors (DSPs) within both the HS4 and DB4 provide precision programmable highpass, lowpass and 50/60Hz notch filtering. Processed signals are converted back to analog in the DB4 and go to XBUS AD2 A/D converter for sampling and recording.

Computer (Maxlab1) - TDT hardware interface
The XBUS handles power and communications for System II modules mounted in XB1 device caddies. Maxlab1 is interfaced to XBUS via a signal processor (AP2 ISA card), used for signal design, and filtering. The connection is done with fiber optic cables. See TDT help (C:\TDT\TDTHelp\TDTHelp.chm) for details of AP2 installation and connections. System 3 modules (currently RP2 only, ZBUS) are connected to Maxlab1 via USB interface.

After monkey presses the lever, the reaction time and other contingencies are evaluated, and if the press is "valid", eyetracker2 dll issues a trigger pulse on TG6 (triggerDLLStimulus() -> IssueTG6Trigger(0x07)). The trigger pulse goes to DIO VSG (In1 breakout box) and activated the vsgPresentOnTrigger function that returns the trigger pulse on the first stimulus presentation frame via Out1, that goes to Trig BNC on AD2 and RP2 and activates trial DAQ.