The Allen-Bradley 1734-TOP3 is a POINT I/O Terminal Base. Implemented as an integrated terminal block, this terminal base (which comes in one piece) is a 12-terminal screw-clamp terminal base used for fast and efficient wiring of industrial automation field devices such as sensors and switches to the POINT I/O system. Vertical or horizontal mounting directly on the DIN-rail is possible, with this terminal base forming backplane communication connections and distributing its field power bus. Incorrect installation of this Input/Output module can be prevented through the use of a mechanical keying setting on the base of this terminal, and its tool-less assembly process is simple and easy to follow.

The main components of this unit are its wiring block, its handle, the interlocking side pieces, the base, its Mechanical Keying, and a DIN-rail Locking Screw (Orange).

The hardware of the 1734-TOP3 terminal base can be described as having  a field power bus voltage supply of 28.8 Volts of DC power or 120 to 240 Volts of AC, with a supply voltage of up to 300 Volts maximum, a maximum terminal current of 8A, a total unit size of around  49 x 12 x 168 millimeters (1.93 x 0.47 x 6.61 inches) while weighing around 79.2 grams (2.79 ounces), with a 0.25 to 2.5 millimeter wire size, (that is 22 to 14 AWG), and a screw torque of 0.6 Nm.

Use the following procedure to install the 1734-TOP3 terminal base: position the base just above the existing units, such as power supplies, and slip the base down. This will interlock its side pieces to the adjacent unit. Press the module firmly to the DIN rail until the terminal base falls into place. The locking screw must come to a horizontal position before the insertion of an I/O module. On its mechanical keying, select the number that matches the I/O module that is meant to be installed. This procedure prevents incorrect installation of an I/O module.

The POINT I/O is electrically connected to the ground over the DIN rail to the frame. Proper grounding can be achieved with a zinc plated yellow-chromate steel DIN rail. The connecting pins are labeled with the numbers 0 to 11, with their connection being determined by the I/O that will be used. No more than two conductors should be wired on any pin.

The 1734-TOP3 terminal base compatible modules are (Mechanical keying in parenthesis): (1) 1734-IB2,1734-OB8E, 1734-IB8, 1734-IB4, 1734-IV2, 1734-IV8, 1734-IV4,1734-OV8E, 1734-OB2, 1734-OB4, 1734-OB8, 1734-OB2E, 1734-OB4E, 1734-OB2EP, 1734-OV2E, 1734-OV4E; (3) 1734-IE2C, 1734-IE2V; (4) 1734-OE2V,1734-OE2C; (5) 1734-CTM, 1734-VTM; (7) 1734-OW2, 1734-OX2, 1734-OW4; (8) 1734-IA4, 1734-IA2, 1734-IM2, 1734-OA2, 1734-IM4, 1734-OA4.