1746-IV8

The Allen Bradley 1746-IV8 is one version of the SLC 500 Digital Input Module series. It comes with 8 channels and operating voltage of 24 Volts DC. The 1746-IV8 module can also be referred to as a Current Sourcing DC Input Module. Its requires use of 14 AWG (2 millimeter) cables for signal termination It is also provided with LED indicators on the front. The operating voltage range of this module is from 10 to 30 Volts DC while the backplane current of this module at 5 Volts is 50 mA, and 0mA at 24 Volts. In its "off" state, the 1746-IV8 has a maximum input voltage of 5 Volts DC. The maximum signal ON delay of this module is 8 milliseconds; the maximum signal OFF delay of is 8 milliseconds. The 1746-IV8 is supplied as open type equipment, intended for use in industrial environments. Stop power before removing this module. Removing or inserting a module with power applied can cause an electrical arc to occur, which can cause personal injury. Electrical arcing can also cause excessive wear to contacts on both the SLC 500 module and its mating connector. Worn contacts may create electrical resistance which can lead to reduced product reliability.

The Allen-Bradley 1746-IV8 is a 24 Volt DC sourcing input module. This module is used to directly interface signaling devices, allowing the SLC 500 control system to recognize change of state for use in the execution of the user program. Typical compatible devices for use with this module are auxiliary contacts, limit switches, sensors and other similarly operating devices.

Each channel of the 17460IV8 accepts an input signal voltage range of 10-30 Volts DC and supports sourcing circuit type. It may be installed to any vacant slot of the SLC 500 chassis and occupies only a single slot of the chassis. It does not require an external power supply to operate as it draws 0.05 Amperes from the backplane.

Each channel of this signal module operates with a signal delay. Both transition - specifically, Off to On and On to Off transitions has an 8-millisecond signal delay with a maximum off-state voltage of 5.0 Volts DC and maximum off-state current of 1 milliampere with a minimum input current of 8 milliamperes @ 24 Volts DC, nominal.

The number of module instances is limited by the I/O capability of the host processor as well as the number of slots available and the number of chassis.

When installing this module to the rack, power must be removed from the rack power supply as the power supply provides the backplane power. This is required to prevent electrical arching which may damage not only the module, but the nearby electronic components as well.