Allen-Bradley 1794-IJ2

The 1794-IJ2 digital Flex I/O frequency module acts as a tachometer with the capability of reporting frequency, acceleration, and direction. The module with the help of the I/O adapter interfaces the programmable controller with field devices ranging from magnetic pickup to flowmeters, to incremental encoders to proximity detectors. The module interfaces the controller with field devices through block transfer programming. Data transfer from the module to the processor is done through the Block Transfer Read (BTR) instruction. The I/O module receives data and configuration from the processor through Block Transfer Write (BTW) instruction. The processor's user program initiates the transfer of data. The module’s 2 inputs accept frequencies from 1 Hertz (Hz) to 32767 Hertz (Hz). The module counts frequency inputs with the help of a high-speed internal clock at a specific time interval defined by the user. The input signals can be magnetic pickups ranging from 500 millivolts to 28 Volts Alternating Current (VAC) peak or proximity probe inputs such as Bently Nevada 3300 - 5 millimeters (mm) /8 millimeters (mm) and vortex flowmeter–6 Volts /3 Volts, etc. The inputs also provide input devices with 24 Volts Direct Current (VDC) supply at 15 milliamperes (mA) maximum. The 2 gate inputs of the module are used to determine the direction. The 2 outputs can be assigned to the input channels with user-programmed frequency and acceleration values. They provide Direct Current voltages (VDC) ranging from 10 Volts to 31.2 Volts, used to set alarms depending on the input conditions programmed by the user. The main components of the 1794-IJ2 I/O module are label identifiers, the key switch position indicator, and eleven indicators. The module requires a terminal base unit to install and connect to the distributed I/O system. Supported terminal bases for the module are Allen-Bradley 1794-TB3G and 1794-TB3GS.