Valve Positioner Control and Monitoring with Only One Device

A completely new feature for modules of this type is that each channel is configurable to allow positioner control on one channel (AO), and position monitoring (AI) on the second channel. Positioners ensure that the actuator is brought into a position specified by the control system. They are often equipped with analog position indicators whose feedback confirms that the position specification has been performed. These can be, for example, stroke or rotation angles, which are typically provided as 4–20 mA signals and reported back to the control system. Previously, a separate isolator module was required for the input and output signal. With the new module now available, these two functions can be used in one device for the first time. If the modules are no longer required for their original signal journey when changes are made to the system, they can continue to be used elsewhere in the system thanks to their configurability. This optimizes warehousing and ensures investment security.

The KCD2-SCS* is an intrinsic safety barrier that can be used for hazardous area applications (approved to ATEX, IECEx, and UL). A version for non-Ex signal conditioning in safe area applications is also available. For each version, there is an option of screw terminals or spring terminals with push-in connection technology. The modules are also certified up to SIL 2 (SC 3) in accordance with IEC/EN 61508 and are therefore suitable for safety applications up to SIL 2, and even up to SIL 3 when used redundantly.

Common applications for the KCD2-SCS* modules in the process industry include process control applications that have both analog input and analog output control loops, safety systems (SIS and ESD) that require SIL 2- or SIL 3-rated intrinsic safety barriers, as well as control loops located in hazardous areas. 

The KCD2-SCS* devices are part of the K-System, which comprises a total of more than 200 isolated barriers and 150 signal isolators. The modules are mounted on a universal power rail. The devices are also supplied with power via this mounting rail profile with insert. 

• Universal 2-channel devices for analog input and output signals
• Each channel can be configured individually as input or output
• Functions: Transmitter power supply for 2-wire transmitters, current driver for positioners
• Current sink and source on control side for analog input signals
• Ex certifications: ATEX, IECEx, UL
• Functional safety: SIL 2 (SC 3) acc. to IEC61508 ed2 (TÜV Rheinland)
• Ambient temperature: -40 °C … +70 °C (-40 °F … +158 °F)
• HART-transparent