The 1771-ALX PLC 5 Local I/O Adapter Module by AB is an I/O chassis module which allows for disconnection of the rack from the BUS without disrupting or shutting down the entire system. The module is located on the leftmost I/O slot of the 1771 I/O chassis and it has a 30m maximum cable length for connection-to-system which can be a combination of 1m (1771-CX1), 2m (1771-CX2), or 5m (1771-CX5) cables.

It has a 1771–CXT terminator plug for termination of the 1771-ALX PLC 5 Local I/O Adapter Module on the BUS with the PLC 5 Programmable Controller and when operational, the adapter module dissipates 6.3W maximum heats and 21.48 BTU/hr thermal dissipation. The module draws a backplane current of 1.2A at 5V DC and is designed to function without de-rating at a temperature range between 0 and 60 0C (32 and 140 0F) at a relative humidity range of 5-95% without condensation. The 1771-ALX has 3 LED light indicators which show the status and also allows users to troubleshoot the module.

The AB 1771-ALX is a Local I/O adapter. This module permits installation of up to sixteen (16) local I/O adapters, allowing rack expansion and ability to host an increased number of 1771 modules. It is installed in the left most slot of every chassis and uses an interconnect cable to establish physical connection to the extended rack. It is compatible for use with 1771-CX1 interconnect cable with a length of 1 meter, 1771-CX2 with a length of 2 meters, and 1771-CX5 with a length of 5 meters.

The chassis distance supported by the 1771-ALX is 30 cable-meters or 98.4 cable-feet. It has a maximum power dissipation of 6.3 Watts and minimum of 5.7 Watts with a maximum thermal dissipation of 21.48 British Thermal Units (BTU) per hour and a minimum of 19.44 BTU per hour. It has a backplane current draw of 1.2 Amperes at 5 Volts DC.

When installing this module, apply the appropriate module keying positions. The upper connector must be set between 54 and 56 while the lower connector must be toggled between 4 and 6. It can be used with any Series A or B 1771 I/O chassis or with any 1771 external or slot power supplies. It comes with three (3) LED indicators that indicate if adapter is ACTIVE; ADAPTER FAULT, and I/O RACK FAULT.

For adapter configuration, it is equipped with adapter switches and adapter plugs. The adapter switches is used to set the I/O rack address and the first I/O group number or the starting module group. The module configuration plug is used to qualify I/O modules and addressing methods. For use with 32-point I/O modules and support any addressing method, set the configuration plug to short the 2 lower pins.

With this setting, the 1771-IX and 1771-IY cannot be used. To set support for the 1771-IX and 1771-IY and any addressing method, short the upper two (2) pins. In this configuration, 32-point I/O modules are not supported.