The Allen-Bradley 1794-IB16D, also cataloged as the 1794-IB16D FLEX I/O Diagnostic Input Module, operates as a dedicated hardware component for field signal acquisition and fault detection within FLEX I/O network architectures.
Hardware Specifications
Parameter
Specification
Model
1794-IB16D
Brand
Allen-Bradley
Origin
USA
Weight
0.20 lbs (0.09 kg)
Dimensions
Standard FLEX I/O module footprint
Operating Temp
-20 to 70 deg C
Power Consumption
Passive backplane load
Operating Voltage
24 VDC nominal
Nominal Input Current
8.8 mA per channel
Input Type
Discrete DC sinking with diagnostics
Number of Inputs
16 channels
Diagnostic Functions
Open-wire fault detection
Mounting Format
DIN-rail / Terminal base mount
Backplane Bus Communication Velocity and Signal Diagnostics
The 1794-IB16D module communicates across the FLEX I/O backplane bus structure, preserving high backplane bus communication velocity during 16-channel discrete signal execution. Equipped with channel-level diagnostic circuitry, the unit actively monitors field input lines to detect open-wire conditions and signal faults in real time. Internal signal isolation prevents field electrical transients from disrupting high-speed backplane data packet transmission between the terminal base assembly and host automation controllers.
Frequently Asked Questions
Q: Can the 1794-IB16D module be installed or removed while the backplane bus is energized?
A: Yes. When mounted on a standard FLEX I/O terminal base unit, the module supports Removal and Insertion Under Power (RIUP) without causing backplane communication disruption to adjacent I/O nodes.
Q: How does the open-wire diagnostic feature function on the 1794-IB16D?
A: The internal diagnostic circuit senses off-state input current leakage; if continuous loop current drops below the designated threshold, an open-wire fault is reported to the controller via backplane status bits.
Field Installation Guidelines
Set the keyswitch on the target FLEX I/O terminal base to the required position for the 1794-IB16D hardware module.
Align the module housing with the base alignment slot and press firmly until the mechanical locking latches click into position.
Wire field input sensors to the terminal base points following standard 24 VDC sinking circuit layout rules.
Segregate DC input wiring from high-voltage AC power conductors in wireways to reduce electromagnetic interference.
Ensure the terminal base mounting rail connects directly to an unpainted, earth-grounded steel DIN rail.
