The 1794-TB3G Flex I/O Terminal Base Unit by Allen-Bradley is a terminal base unit module that is installed with a panel or DIN rail and provides terminal I/O wiring connection points. It has 36 maximum input/output terminal points with 2 common terminals and 2 positive voltage terminals. It has 10 Chassis Ground Terminals and is built for uses in 10A and 31.2V DC applications. It provides I/O termination through the Grounded Screw Clamp and has a terminal screw torque of 0.56 x 0.79 Nm (5-7lb-in). The I/O modules are connected to the I/O bus through the 1794-TB3G and it also provides a FLEXBUS current of 640mA at 5V DC with a 2A maximum I/O terminal current. 

It has a Voltage/Communication terminal rating of 125V DC/AC and 10A at 50-60 Hz and it delivers a maximum 50V (continuous) voltage isolation using the Basic Insulation Type tested for 60s at 2121V DC between the Field Wiring Terminals and FLEXBUS or any lesser module. The 1794-TB3G uses a 0.21 x 1.3 mm2 (24-16 AWG) stranded size copper wire rated at 75 °C (167 °F) with 1.2 mm (3/64 in) insulation and the whole module is given the T4A and IEC TA temperature codes. It functions without de-rating at a temperature range between -20 and 70 °C (-40 and 158 °F) at 5-95% non-condensing ambient relative humidity is stored at a factory-specified -40-85 °C (-40-185 °F) temperature range. It is built to retain standard functions at an operational shock rating of 30G and a vibration of 5G at 10-500Hz.