1771-ASC

The 1771-ASC Universal Remote I/O Adapter Module by Allen-Bradley is an adapter module which provides an interface between the programmable controller and the remote I/O. The module is fitted in the leftmost slot of the 1771 I/O chassis and has a variable baud rate of 230.4K Baud, 115.2K Baud, and 57.6K at 2500ft, 5000ft, and 10000ft Chassis distance using 1770-CD interconnection cable. The 1771-ASC draws a backplane current of 1 Ampere at 5Volt and has a thermal dissipation of 17.06 BTU/Hr with 3W power dissipation. The module is keyed to the chassis backplane connector by connecting the upper connector between pins 54 and 56 and the lower connector between pins 16 and 18 of the backplane connector. The 1771-ASC uses the 1771-WB Field Wiring Arm with a 7 by 9 pound-inches screw torque for connection of analog signals and termination is provided by either an 82 or 150-ohm termination resistor. Its circuitry uses a conductor cable of 20AWG size stranded copper wire with 3/64 (1.2mm) wire insulation and a single wire peer terminal. The 1771-ASC’s functional temperature ranges between 0 and 60 0C at 5-95% non-condensing relative humidity, and is CSA, UL, CE, and C-TICK certified.

The 1771-ASC is a Remote I/O adapter that is used to establish connection to devices enabled for Remote I/O communication. This module supports Remote I/O speeds of 57.6K baud for 10000 ft and 230.4K baud for2500 feet. The 1771-ASC is basically a 1771-AS or a Remote I/O adapter module that is pre-installed with a swingarm.

This module is compatible for installation in a PLC5 chassis having a mix of I/O module with different channel densities. Specifically, it supports I/Os with 4, 6, 8, 16 or 32 channels. This module is capable of receiving and sending data to the designated I/O scanner in serial manner, read and write data to and from analog and discrete input module in parallel and using the same manner, read and write data to and from discrete and analog output modules.

This module supports addressing methods supported by PLC 5 platform such as ½ slot, 1-slot and 2-slot addressing. During power-up, this module automatically check the system configuration for consistency and scans all chassis except the final Four (4) slots for a better scan time and space saving for the I/O image.

With Remote I/O communication, Block Transfer Read (BTR) and Block Transfer Write (BTW) instructions will be utilized.

This module is provided with sets of DIP switches to configure the operational settings of the module such as baud rate, I/O assignment, rack number and other important settings. It is also provided with active status indicators for continuous feedback of the module’s operation. These indicators are ACTIVE, ADAPTER FAULT, and I/O RACK FAULT. For the Active status, the LED light should be Green to indicate normal operation. When an adapter fault is experienced, Red light illuminates while for Rack Fault, RED led activates.