The Stonel FOUNDATION Fieldbus I/O modules have an auxiliary 4 to 20mA input and a 4 to 20mA output which is powered from the supplemental 24VDC supply bus. Additional savings may result from connecting the 4 to 20mA device directly to the Stonel I/O instead of running wires back to I/O at the controller. The additional analog input would be represented as an AI (Analog Input) function block as part of the StoneL device description.
The 4 to 20mA instrument may be conveniently wired directly into the StoneL I/O module. With a conventional system the control would need a 200 foot run back to the controller. Other savings would result from:
- Reduction in design time because of simpler conduit and cabling systems.
- Reduction in conduit and cabinetry space.
- Right first-time wiring and easier trouble-shooting.
- Faster commissioning.