1771-IFF

Product Overview

The 1771-IFF from Allen-Bradley is a fast analog input module designed for high-speed data acquisition in PLC-5 systems.

Inputs and Module Location

• Inputs per Module: 16 single-ended; 8 differential low-level

• Module Location: 1771 I/O chassis, 1 slot

Input Voltage and Current Ranges

• Voltage Ranges (Nominal): +1 to +5 V DC, 0 to +5 V DC, -5 to +5 V DC, -10 to +10 V DC, 0 to +10 V DC

• Current Ranges (Nominal): +4 to +20 mA, 0 to 20 mA, -20 to +20 mA

Accuracy and Resolution

• Resolution: 12-bit binary; 12 bits plus sign for bipolar ranges

• Accuracy: 1.0% of full-scale range at 25°C

• Linearity: ±1 LSB

• Repeatability: ±1 LSB

Protection and Isolation

• Isolation Voltage: Tested to 850 V DC for 1 s

• Input Overvoltage Protection: 35 V max (voltage mode), 8 V max (current mode)

• Input Overcurrent Protection: 30 mA (current ranges)

• Common Mode Voltage: ±35 V

• Input Impedance: >10 MΩ (voltage ranges), 250 Ω (current ranges)

• Common Mode Rejection: 80 dB, DC–120 Hz

Power and Thermal

• Current Requirements: 500 mA at 5 V DC from I/O chassis backplane

• Power Dissipation: Backplane 2.5 W max; Inputs 2.5 W max

• Thermal Dissipation: 17 BTU/hr max

Output and Scaling

• Unscaled BCD/Binary Output to Processor: 0000–4095 for polar ranges; -4095–+4095 for bipolar ranges

• Engineering Units Output: +9999 with selectable scaling

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