FLEX Ex Terminal Base Units Introduction

FLEX Ex combines a terminal strip and intrinsic-safety isolation with an I/O interface. Use the terminal strip on the terminal base to wire your field devices directly. The FLEX Ex design also offers these features:

• modularity for distributed IS systems

• all of the features of a larger, rack-based system

• installation near the field devices to reduce wiring costs and complexity

• terminations for field wiring eliminating the need for marshalling or extra terminal strips

• ControlNet-based networking solution in the hazardous area with ControlNet Ex products

• DIN-rail mounting

FLEX Ex provides additional value if system problems develop. The terminal base lets you remove and insert I/O modules under power without rewiring or disrupting your system. Combining your field-wiring terminations, IS isolation, and the I/O interface into the same location saves you time, money, and makes your system easier to maintain and troubleshoot. Additional benefits include:

• galvanic isolation between the I/O backplane, input circuitry, and power supply

• dual-fault protection IS circuits provide the highest fault tolerance

• I/O circuitry provides full IS field-device protection

• the modules themselves are IS protected for installation in hazardous environments FLEX Ex I/O modules may be removed and inserted while operating under power. Network module maintenance and cable connections can be made in the hazardous area while the system is in operation and the area is hazardous.

FLEX Ex Typical Configurations

The following are typical configurations of FLEX Ex I/O in an intrinsically safesystem:

• FLEX Ex I/O modules are interfaced through a ControlNet Ex I/O adapter module to a coax ControlNet segment that is confined to the hazardous area. This coax ControlNet Ex segment is interfaced through ControlNet Ex coax drop repeater module and ControlNet Ex fiber media port adapter to a fiber-optic ControlNet segment, which is fed through from the safe area. A FLEX Ex power supply powers the repeater module, fiber media port adapter, ControlNet Ex I/O adapter module, and I/O modules individually. This configuration is best for long distances and a large number of nodes.

• The FLEX Ex ControlNet barrier allows connection to a ControlNet Ex I/O adapter module in the hazardous area via coax directly from the safe area. The barrier is mounted in the safe area. This is more economical for intermediate distances and nodes.

• Sensors and actuators in a hazardous area can be connected to FLEX Ex I/O modules, which are connected through a bus isolator module and connector to a FLEX I/O adapter in a safe area thus allowing connectivity to DeviceNet, ControlNet, Universal Remote I/O, and EtherNet/IP. This configuration may be most economical for low-point applications or when networks other than ControlNet are required.

• FLEX Ex I/O modules in a hazardous area can be connected through an extender cable to a FlexBus feed-through connector in an explosion-proof enclosure. Inside the enclosure, the feed-through connector is connected through a FLEX Ex extender cable, and then a bus isolator module and connector, to a FLEX I/O adapter.