1771-NIVR

The Allen-Bradley 1771-NIVR is an intelligent high-resolution I/O module from the 1771-N family of I/O modules. It is equipped with 4 voltage/current inputs rated for ±5V (±20mA) and 4 RTD (resistance temperature detector) inputs rated for 1-650ohm. The 1771-NIVR is designed for use with the following programmable controllers: PLC-3, PLC5-250, and PLC-5. The maximum I/O backplane current draw and maximum power dissipation of a single 1771-NIVR module at 5V are 1.2A and 6W. respectively. The 4 voltage/current inputs are designed for a working range of ±5.5V (±22mA with a resistor)., an input resolution of 168µV/bit (0.7µA/bit), and an input impedance greater than 10 megaohms. Overvoltage protection is provided for the inputs and is rated at 140V AC RMS.

The 1771-NIVR’s 4 RTD inputs are rated for 1 – 650ohm. The input range is selectable depending upon the type of RTD used: with the 100ohm Platinum RTD (European standard), the range is -200 - +870°C (-328 - +1598°F), with the 100ohm Platinum RTD (U.S. standard), the range is -200 - +630°C (-328 - +1166°F), with the 10ohm copper RTD, the range is -200 - +260°C (-328 - +500°F) and with the 120ohm nickel RTD, the range is -80 - +320°C (-112.1 - +608°F). The maximum value for the input resolution is 10milliohm/bit (at 16 bits unipolar). With the 100ohm Platinum & 120ohm nickel RTDs, the resolution is 0.03°C (0.06°F) and with the 10ohm copper RTD, the resolution is 0.3°C (0.5°F). For the display, the default resolution is 0.01ohm / 0.1°C. The typical value for the RTD excitation current is 1 mA. The offset drift and gain drift are ±25 milliohm/°C and ±50 ppm/°C, respectively. The calibration values are 1/649ohm. The working range of temperatures supported by the 1771-NIVR is 0 to 60°C.