1771-CX1

The Allen-Bradley 1771-CX1 Local I/O Bus Terminator Cable features a backplane current of 1.0 Amps maximum. The wiring arm of this module is 1771-WN and it also has a module scan time of 1.3-5 ms. This cable exhibits a length of 3.28 ft. The cable has only one slot and has a storage temperature of -40-185 °F, an operating temperature of 32-140 °F, and it weighs 0.9 kg. The cable has a conformal coating and has dimensions of 3.5 × 6.5 × 2.0 in. The 1771-CX1 cable features an electronic relay which provides it with an economical design for power applications.

The electromechanical relay featured in the 1771-CX1 cable is not recommended for low voltage or low current applications. Dry-relays are generally faster than electromechanical relays. The electromechanical relays are therefore not recommended for environments with contaminants like nitrogen, ammonia, acid, or chlorine because they have not been sealed hermetically. Relays exhibit a finite number of operations during their life and so this varies depending on the current loads and the voltages applied relative to the design specifications of the relays. A relay which has a tendency to operate at the same load conditions will always have a very predictable life.

The wiring of the 1771-CX1 cable between the module and the load is able to create a specific amount of capacitive loading required by the relay contacts. During the contact closure, this capacitance is discharged. Additional wear on the contact can be caused by the resulting flow of peak current. This effect can easily be avoided by keeping the cable length as short as possible. If possible, the user can also insert a resistor in a series with a load. The resistor should then be located as close as possible to the field wiring arm.