The 1771-IT 60V DC sink digital input module from Allen-Bradley houses 8 inputs that operate at a voltage of 12-72V DC. The backplane current that this device operates on is 74mA and the off-state current is a maximum of 1.3mA. This I/O device is compatible with any kind of source switching devices including electro-mechanical transmitters, panel switching devices, and dry contact switches. This device connects to the input module that is made through to the terminal field wiring arm. You need to attach this arm to the pivot bar placed at the bottom of the I/O chassis. You can remove or uninstall the module without disconnecting it from the wires because the arm pivots upwards and connects firmly with the module of the wiring. This 1771-IT device module can be used as a DC output driver module that directly steers terminals on a fast-response DC input module. The input voltage for this particular I/O device is 12-24V DC. The input voltage for this device ranges from 0V minimum to 4V maximum. The input current used by the 1771-IT is 8m at 12V DC and 24mA at 24V DC. The 1771-IT module gets the power supply through the 1771I/O chassis backplane. This feature stops the chassis backplane from getting overloaded as well. The typical AC signal delay in an off-state range from 45 (+/- 15)ms. The typical DC signal delays off ranges to a maximum of 50ms. This model of I/O module is also rack mountable.
ManufacturerRockwell Automation
BrandAllen-Bradley
Part Number/Catalog No.1771-IT
Module TypeDigital DC Input Module
Number of Inputs8 Inputs
Voltage Category10-60 Volts DC, Sink (Source Load)
DC Operating Voltage12-72 Volt
Backplane Current74 Miliamperes
Max DC Off-State Current1.3 Miliamperes
Typical DC Signal Delay (On)0.6 (+/- 0.2) ms
Typical DC Signal Delay (Off)50 ms
Wiring Arm1771-WH
Model StatusEarlier Model
Typical AC Signal Delay (Off)45 (+/- 15) ms
MountingRack Mountable