Active Field Distributor AFD4

Active Field Distributor AFD4 RAILMOUNT

Active Field Distributor AFD8

Active Field Distributor AFD

Active field distributors (AFD) can be operated in environments in accordance with Division 2, Zone 2 or Zone 22. It is offered with the following models:

• AFD4, AFD4 RAILMOUNT or AFD4 FM with 4 spur line connections for 1 field device each
• AFD8 with 8 spur line connections for 1 field device each

An AFD4/AFD4 RAILMOUNT/AFD4 FM can therefore integrate up to 4, and an AFD8 up to 8 standard-compliant FF (FOUNDATION Fieldbus H1) field devices via short-circuit proof spur line connections to a fieldbus segment (line/ring) with automatic bus termination.

The FF fieldbus segment can be connected to a single or redundant PROFIBUS DP via an FF gateway and can thus be seamlessly integrated into the SIMATIC PCS 7 process control system.

Up to 8 active field distributors AFD with a total of up to 31 connected field devices can be operated for each fieldbus segment. The number of field devices is also limited by the current consumption of the field devices. A maximum of 60 mA per spur line and a maximum of 0.5 A per segment is available for the field devices.

An AFD in a ring segment can be replaced during operation without resulting in failure of the segment.

For compliance with IP66 protection, it is necessary to protect unused spur line connections using plugs.

Based on the AFD4, two product versions with different intentions were developed with the AFD4 RAILMOUNT and the AFD4 FM:

Specific product features of the AFD4 RAILMOUNT

The AFD4 RAILMOUNT is supplied without die-cast aluminum enclosure; it is a product model of the AFD4 active field distributor with flexible installation options. It can be installed on a DIN mounting rail into an enclosure of choice, for example, an enclosure made of stainless steel, die-cast aluminum or plastics.

Specific product features of the AFD4 FM

The AFD4 FM with cFMus approval is adapted to the special requirements for product models of the AFD4 active field distributor in the USA and Canada. The AFD4 FM features threaded plugs ex factory, because the cable glands of the AFD4 do not conform to the requirements of cFMus.

The threaded plugs for connecting the main and spur lines must be replaced by the cable glands and cables listed by UL or CSA. This must conform to the US National Electrical Code (NEC) and Canadian Electrical Code (CEC). The user is responsible for the selection and ordering.

Available suppliers for suitable cable glands:

• Cooper Capri SAS
• CMP products

Due to the larger bushing for the main line (M20 instead of M16), sheathed main line cables can also be used for AFD4 FM.

The relevant requirements of the US National Electrical Code (ANSI/NFPA?70 NEC) must be met for the installation of the AFD4 FM.

AFDiSD active field distributor

AFDiSD active field distributor

The AFDiS (Active Field Distributor intrinsically Safe) is an active field distributor for operating environments in accordance with Ex zones 1/21 and 2/22. It can integrate up to 6 intrinsically-safe FF field devices into an FF fieldbus segment (line/ring) via its intrinsically-safe, short-circuit-proof spur line connections. Instead of the spur line, it is also possible to use a subsegment for 3 to 4 devices with a max. length of 500 m at connection S1 of the AFDiS. The spur lines with Ex [ia] type of protection as well as the subsegment can be routed into Zone 0/20.

Up to 5 AFDiS field distributors with a total of up to 31 field devices can be operated in a fieldbus segment. The limitation to 5 field distributors is also mandatory for mixed operation of AFD and AFDiS.

The number of field devices per segment additionally depends on the current consumption of the devices. A current of 0.5 A is available for all field devices of the segment.

With the integrated repeater function, the AFDiS has the following advantages compared to the AFD:

• Spur line lengths are independent of the total number of spur lines in the bus segment.
• Spur line lengths need not be be taken into account when determining the total length of the bus segment.

In environments in accordance with Ex zone 2/22 or in non-hazardous areas, an AFDiSD in a ring segment can be replaced during operation without failure of the segment.

For compliance with IP66 protection, it is necessary to protect unused spur line connections using plugs.

Active Field Splitter AFS

The AFS active field distributor (Active Field Splitter) connects an FF line segment with a redundant Compact FF Link pair. The AFS interconnects the FF line segment with the active Compact FF Link in each case.

The FF line segment can be connected to the AFS via one or two (center infeed) out of a total of 4 identical Y-connectors. In the case of the center infeed, the line segment is looped through via the two Y-connectors.

For compliance with IP66 protection, it is necessary to protect unused connections using plugs.

AFS: Active Field Distributor for FOUNDATION Fieldbus H1