Features:
- Analog Signal Interface for 4-20mA Current Loop Devices on the 1771 I/O Chassis Backplane
- Sixteen-Bit Input Resolution with Thirteen-Bit Output Capability for Precision Process Control
- Compatibility with PLC-3, PLC-5, and PLC-5/250 Programmable Controller Systems
The Allen-Bradley 1771-NBSC/C Sourcing Input Module serves as an analog I/O interface within the 1771 modular control system, providing six 4-20mA current input channels and two 0-25mA current output channels for continuous process variable monitoring and control. It continuously conditions incoming analog current signals from field transmitters and delivers regulated output signals to final control elements, distributing these signals through the 1771 I/O chassis backplane to support steady-state operation of the programmable controller. The 1771-NBSC/C draws a maximum of 2.6A from the chassis backplane and dissipates 13W during operation. The module requires the RTP-4 device for proper termination and signal integrity.
The 1771-NBSC/C provides essential analog input and output functions within the control rack, and is a critical component of the process control path, directly affecting the accurate acquisition and delivery of continuous process data. One 1771-NBSC/C module occupies a single slot in the 1771 I/O chassis and must be properly seated for reliable backplane communication. Power must be disconnected before removing or installing the 1771-NBSC/C module to prevent electrical damage and ensure personnel safety.
For the six current input channels, the 1771-NBSC/C accepts a range of 0.1 – 21 mA with a resolution of 330nA per bit at 16 bits unipolar, and the input impedance reaches a maximum of 300ohm. The module supplies 20 – 30V DC loop power for 0-20mA current loops and provides input overvoltage protection rated at 24V DC continuous. The 1771-NBSC/C requires 5 seconds to detect open input conditions and offers a minimum normal mode rejection of 50/60 dB with a typical common mode rejection of 150 dB. The offset drift is ±200nA/°C and the gain drift is ±95 ppm/°C. The input bandwidth is 9Hz and the calibration values are 1.000mA/21.000mA, with under-range and over-range thresholds at 3.2mA and 21mA respectively.
The 1771-NBSC/C Allen-Bradley Sourcing Input Module may still be available for purchase and support from Apter Power beyond End-Of-Life (EOL) by the manufacturer (OEM).
Allen-Bradley 1771-NBSC/C Sourcing Input Module Manuals,Datasheets,Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
Allen-Bradley 1771-NBSC/C Sourcing Input Module Specs
General
- Manufacturer Allen-Bradley
- Model 1771-NBSC/C
- Condition New Original ready stock
- Product Family 1771-NIS,1771-NB4S,1771-NBSC
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not included with this equipment unless listed in the above stock item description. All prices are shown in USD.
- Process Instrumentation: Monitors flow meters, pressure transmitters, and temperature sensors.
- Loop-Powered Integration: Powers and reads 2-wire loops using internal 20–30V DC power.
- Precision Actuator Control: Regulates control valves and variable speed drives via 13-bit outputs.
- Legacy Plant Support: Maintains PLC-5, PLC-3, or PLC-5/250 control architectures.
- Environment Class: Rated for Pollution Degree 2 and Overvoltage Category II.
- Enclosure Type: Open-type equipment requiring a tool-accessible, protective enclosure.
- Altitude: Operates up to 2000 meters without performance derating.
- Signal Protection: Features continuous 24V DC input overvoltage protection.
- Signal Filtration: Provides 150 dB common-mode and 50/60 dB normal-mode rejection.
- Backplane Interaction: Connects to the 1771 chassis, drawing 2.6A at 5V DC.
- Ladder Logic Instructions: Uses Block Transfer Write (BTW) and Block Transfer Read (BTR).
- Network Capabilities: Works over Data Highway Plus (DH+), Remote I/O (RIO), ControlNet, and DeviceNet.
- Field Wiring: Connects through a detachable 1771 field wiring arm for easy swaps.