1797-CEC | Allen Bradley | FLEX Ex Bus Connector Module

Configured for communication bridge execution in mixed-signal architectures, the Allen Bradley 1797-CEC (1797-CEC FLEX Ex Bus Connector Module) provides direct physical and electrical execution of inter-module data linking between standard FLEX I/O and Intrinsically Safe (IS) FLEX Ex segments.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks

The 1797-CEC functions as a physical backplane bus communication velocity adapter, maintaining signal integrity when transitioning from standard I/O platforms to hazardous-area segments. The module enables I/O density scaling by supporting up to 8 additional FLEX modules per group, while ensuring that deterministic network timing is preserved across the bus expansion. Firmware flash compatibility is governed by the host communication adapter, as the 1797-CEC operates as a passive-active physical layer interface. Deterministic data exchange between non-IS and IS zones is maintained through the internal master and slave backplane connector paths, ensuring that signal latency remains within nominal tolerances for the specific PLC backplane configuration.

Frequently Asked Questions

Q: Does the 1797-CEC provide galvanic isolation?

A: The module manages the physical interface for bus expansion but relies on the associated FLEX Ex communication adapter or isolation barriers for specific galvanic isolation requirements between the non-IS and IS zones.

Q: Is this module compatible with all standard FLEX I/O adapters?

A: Compatibility is contingent on the specific backplane connector interface of the 1797 FLEX Ex series. Verify that the communication adapter supports the extended bus architecture provided by the 1797-CEC.

Field Installation Guidelines

1. Mounting: Secure the 1797-CEC onto a standard 35 mm DIN rail. Ensure the module is properly seated to maintain the physical connection between the standard I/O bus and the FLEX Ex bus.
2. Bus Connection: Engage the master backplane connector on the host side and the FLEX I/O backplane connector on the expansion side. Verify that all locking mechanisms are fully latched.
3. Environmental Compliance: Ensure the installation site meets the IP20 rating requirements. Maintain ambient temperatures within the -20 to 70 deg C range to prevent accelerated degradation of the internal connector pins.
4. Wiring Segregation: When installing in cabinets, keep non-IS and IS signal wiring segregated according to local regulatory standards for hazardous area installations.
5. Shock Protection: Given the 30 g peak acceleration rating, ensure the DIN rail is rigidly mounted to the cabinet backplane to avoid mechanical fatigue of the connector assemblies in high-vibration environments.