Specifications

Publication 1794-SG002D-EN-P - May 2012
84 Select FLEX Ex I/O Communication Adapters and Distribution Method
1797-BIC Bus Isolator Module and 1797-CEC FlexBus Connector
The bus isolator modules, 1797-BIC and -CEC, allow you to configure FLEX Ex
modules and FLEX I/O modules on the DIN Rail when attached to the same
adapter and grouped together on appropriate sides of the bus isolator module.
This highly flexible, cost-effective solution combines intrinsically safe and
non-intrinsically safe systems.
Intermixed system can be configured for use in the:
• safe area much like traditional IS and I/O systems
• hazardous and safe control equipment where the distance of physical
separation is short
• FLEX Ex I/O with communication adapters that are not intrinsically safe
The 1797-BIC and -CEC modules provide an IS-compatible mechanism to
separate two sections of the backplane, allowing IS and non-IS field-device wiring
to the same I/O group. It converts hazardous power to IS-safe power to run one
side of the bus receiver/transmitter circuitry and IS-safe power to slave side
modules. A total of eight I/O modules (1794 FLEX I/O or 1797 FLEX Ex I/O)
may be attached to the adapter.
Any FLEX I/O communication
adapter that supports FLEX Ex
FLEX I/O
1797-CEC
Bus isolator
1797-BIC
FLEX Ex
Field wiring to Zone 0 Class I, II,
II Division 1, Groups A-G
FLEX Ex
power supply
Nonhazardous Area
or
Class I Division 2
Groups A-D
or Zone 2
Any FLEX I/O communication
adapter that supports FLEX Ex
Nonhazardous Area
1797-CEC
1797-BIC
1794--CE1 or 1794-CE3 cable
Hazardous Area
Field wiring to
Zone 0
FLEX Ex
power supply