The Allen-Bradley 1761-L20BWB-5A is a part of the MicroLogix 1000 family of controllers. It is a small programmable controller that fits in small panel space. For communication, it has a built-in RS-232C port for DF1 protocol, Point-to-point, DH-485, DeviceNet, and EtherNet/IP communication. These communication types support direct connection, half-duplex slave protocol for SCADA applications, program upload and download, peer-to-peer communication, etc. It requires simple programming in ladder logic using RSLogix 500 software, Hand-Held Programmer (HHP), MicroLogix 1000, or PLC 500 A I Series software. It has more than 65 instructions for applications like high-speed counting, sequencing, and shift registers. It can program and operate in up to 5 different languages.
The 1761-L20BWB-5A controller has 25 I/O with 24V DC sink/source power for 12 inputs, 2 voltages (±10V) and 2 current (0 – 20mA) analog inputs, 2 contact outputs, and 1 voltage/current (0 – 10V, 4 – 20 mA) analog output. It has a real input power of 7W at 24V DC. It has 1500V AC isolation voltage and a 1K-word EEPROM. It has a program scan time of 2ms and I/O scan time of 0.21ms. It has a maximum of 32 counters and 40 timers.
The 1761-L20BWB-5A controller has a master control relay safety feature. It is installed using a DIN rail or mounting screw method with adequate spacing in the enclosure for heat dissipation. It is intended for use in a category II non-hazardous industrial environment with a 0 – 55 °C (32 – 131 °F) operating temperature and a 20g maximum operating shock.