Revision 3.1 - 129 - March 2010
APPENDIX 6: F
OUNDATION FIELDBUS SEGMENT AND LOOP
DRAWINGS
Four drawings are provided illustrating both FOUNDATION fieldbus segment drawings
and instrument loop drawings using two different technologies. The first two drawings
are based upon "brick" style field connectors and assume a significant distance
between the device couplers. This layout should not be used for device couplers inside
the same junction box. In that case, the trunk line will be connected directly to the
individual device couplers.
A segment drawing (Figure A6.1) illustrates how all the devices on one segment are
connected back to the H1 interface on the host system. Figure A64.1 shows six (6)
FOUNDATION fieldbus devices that are connected onto one H1 segment.
An instrument loop drawing (Figure A6.2) illustrates all the devices associated with the
implementation of one control loop. In this case, the control loop comprises a fieldbus
transmitter (flow) and a 4-20 mA level transmitter connected to a 4-20 mA control valve.
In this instance, the loop drawing combines both current (4-20 mA) and digital
(FOUNDATION fieldbus) technologies onto one drawing.
The third drawing (Figure A6.3) is another example of a segment drawing using terminal
blocks in the field junction box (versus a "brick" style connector). In this segment
drawing, four (4) FOUNDATION field devices are connected onto one segment.
The fourth drawing (Figure A6.4) is another example of an instrument loop drawing.
This time, the level transmitter and the level control valve are implemented via
F
OUNDATION fieldbus, whereas the flow transmitter is implemented via 4-20 mA. Again,
terminal blocks are used in the H1 segment implementation consistent with the
associated segment drawing (Figure A6.3).
All drawings are output from SmartPlant Instrumentation (SPI) (previously known as
INtools) using the Enhanced SmartLoop (ESL) functionality of the wiring module.
Project specific drawings may be slightly different, depending on specific project
decisions on the representation of field devices, terminal blocks, wiring colors and field
junction boxes. However, the basic layout will be similar, given the ESL output limits.