1797-IBN16

Features:

• Bridge Between Hazardous Area NAMUR Field Devices and Standard FLEX Ex Control Architecture
• Integrates NAMUR Signal Processing with Intrinsic Safety Certification for Explosive Environments
• Functions Alongside the 1797-TB3 and 1797-TB3S Intrinsically Safe Terminal Base Units

The Allen-Bradley 1797-IBN16 serves as the 16-Channel NAMUR Input Module in a FLEX Ex hazardous area I/O rack, providing reliable discrete input acquisition from NAMUR-compatible sensors and switches to all modules within the control system. It continuously processes incoming field device signals (9.5 VDC voltage rating, 2.1 mA ON state current, 1.2 mA OFF state leakage current) and transmits these digital input states through the rack backplane to support steady state operation of all monitors and control modules. Selectable input delay timing is configurable with the 1797-IBN16, offering settings of 1 ms, 2 ms, 3 ms, 5 ms, 9 ms, 17 ms, and 33 ms for both OFF to ON and ON to OFF transitions with a default of 1 ms, allowing precise signal conditioning in the event of contact bounce or rapid state fluctuations. The 1797-IBN16 maintains comprehensive hazardous area certifications including Ex ia IIB/IIC T4, AEx ia IIC T4, Class I, II, III Division 1 Group A-G T4, and Ex ib IIB/IIC T4, AEx ib IIC T4, Class I, Division 1 Group A-D T4, enabling direct mounting in Class I, II, and III / Division 1, Zone 1 and Zone 22 application areas.

The 1797-IBN16 delivers essential input functions for the entire hazardous area I/O rack, and constitutes a critical component of the safety instrumented path, directly affecting the proper, normal operation of the overall process monitoring system in explosive atmospheres. One 1797-IBN16 module provides sixteen discrete sinking input channels per installation, with each channel being NAMUR compatible and non-isolated within the single group architecture. The 1797-IBN16 occupies a standard module position in the rack and is always mounted directly to the equally rated 1797-TB3 or 1797-TB3S terminal base (the dedicated intrinsically safe terminal base units), as it is not compatible with standard Flex I/O terminal bases.

For comprehensive diagnostic monitoring applications, the 1797-IBN16 incorporates a built-in LED indicator system integrated within the module housing. In addition to standard signal acquisition operation, the dual-color indicator configuration performs continuous channel status visualization. The 1797-IBN16 diagnostic display system executes fault indication using the internal circuitry specified in the module design. Using this method, the status monitoring system continually observes the condition of all sixteen channels. If the system detects that a specific input channel has transitioned to a fault state (outside normal NAMUR operational parameters), it will automatically illuminate the corresponding red fault indicator while the yellow status indicator displays the active input state, providing immediate visual feedback in the channel indicator array.