The Allen-Bradley 1797-BIC, also cataloged as the 1797-BIC FLEX Ex Bus Extender Isolator Module, operates as a dedicated hardware component for galvanic isolation and signal propagation across intrinsically safe backplane segments within FLEX Ex I/O systems.
Hardware Specifications
Parameter
Specification
Model
1797-BIC
Brand
Allen-Bradley
Origin
USA
Weight
1.32 lbs (0.60 kg)
Dimensions
Standard FLEX Ex module footprint
Operating Temp
-20 to 70 deg C
Power Consumption
2.5 W
Input Voltage Range
18-32 VDC
Bus Current Rating
150 mA
Module Type
Bus Isolator / Extender Module
Mounting Format
DIN-rail / Base unit assembly
Backplane Bus Communication Velocity and Signal Isolation
The 1797-BIC module establishes an intrinsically safe galvanic isolation barrier across backplane expansion segments in FLEX Ex chassis layouts. Operating with a nominal backplane current draw of 150 mA across an 18-32 VDC supply range, the unit maintains deterministic backplane bus communication velocity while preventing energy transfer into hazardous location zones. Channel-to-bus logic circuits ensure that transient bus noise and voltage spikes are clamped within specified safety thresholds without degrading high-speed serial packet transmission between local adapter bases and remote I/O terminal blocks.
Frequently Asked Questions
Q: Can the 1797-BIC module be removed or inserted under field power?
A: Hot-swapping the 1797-BIC must follow hazardous location field protocols. While the module is intrinsically safe, removing the unit interrupts backplane bus communications to downstream FLEX Ex modules. Powering down the local segment is recommended to maintain system deterministic control states.
Q: What is the primary purpose of the 1797-BIC in a FLEX Ex system architecture?
A: The 1797-BIC serves as a physical galvanic barrier and signal interface between non-intrinsically safe or standard power segments and intrinsically safe FLEX Ex backplane I/O clusters, preserving signal integrity across high-density I/O node layouts.
Field Installation Guidelines
Mount the module onto the standard DIN rail adjacent to the target FLEX Ex terminal base assembly, ensuring positive mechanical latch engagement.
Verify that field wiring connections to the 18-32 VDC power supply adhere to proper polarity standards before applying bus power.
Keep field signal cables segregated from high-voltage AC lines, routing cables through dedicated wiring channels.
Ensure the DIN-rail grounding shoe makes clean, low-impedance mechanical contact with an unpainted, earth-grounded metal rail surface.
Secure all module locking tabs to prevent vibration-induced disengagement in heavy industrial environments.
