DeltaV SIS™ Logic Solver  SLS1508

„ World’s first smart SIS Logic Solver 

„ Integrated, yet separate from the control system 

„ Easy compliance with IEC 61511 

„ Scales to fit any size application 

„ SIL 3-rated „ Online addition of Logic Solvers

Introduction 

The DeltaV SIS™ system, part of Emerson’s smart SIS, ushers in the next generation of Safety Instrumented Systems (SIS). This smart SIS approach uses the power of predictive field intelligence to increase the availability of the entire safety instrumented function.

Benefits 

The World’s first smart SIS. Research shows that over 85% of all faults in SIS applications occur in field instruments and final control elements. The DeltaV SIS system has the first smart Logic Solver. It communicates with intelligent field devices using the HART protocol to diagnose faults before they cause spurious trips. This approach increases process availability and reduces lifecycle costs.

Integrated yet separate. Safety standards insist on separation of the control and safety systems to remove any possibility of a common failure affecting both layers of protection. End users require an integrated configuration, maintenance, and operations environment. The DeltaV SIS system has a unique solution to this problem; implementing safety functions with dedicated hardware, software, and networks while being seamlessly integrated at the workstations.

Scales to fit any size application. Whether you have an isolated wellhead or a large ESD/fire and gas application, the DeltaV SIS system scales to provide you with the safety coverage you need for your SIL 1, 2 and 3 safety functions. Each Logic Solver has dual CPUs and sixteen channels of I/O built into it. This means that no additional processors will ever be required to expand the system, since each Logic Solver contains its own CPUs. Scan rate and memory usage are constant and independent of system size.

SIL 3-rated. DeltaV SLS 1508 Logic Solvers are installed in redundant pairs for increased process availability of your SIS loops.

Redundant architecture includes: 

„ Dedicated redundancy link 

„ Separate power supply to each Logic Solver 

„ I/O published locally every scan on redundant peer-to-peer link 

„ Same input data for each Logic Solver

Online addition of Logic Solvers. The system checks for new hardware every scan, so equipment can be added to an on-line system in real time. Online addition of new logic solvers means your process does not get interrupted. As new equipment is added, the DeltaV Explorer software recognizes it and makes it ready to be configured.

Product Description

This section provides general information on DeltaV SIS hardware. Refer to the Installing Your DeltaV Distributed Control System manual for more information on DeltaV system equipment.

DeltaV SIS Equipment

A DeltaV distributed control system consists of carriers, one or more I/O subsystems, controllers, power supplies, workstations, and a control network. The DeltaV SIS system consists of: 

„ Redundant Logic Solvers (SLS 1508) and termination blocks 

„ SISnet Repeaters (see separate product data sheet) 

„ Carrier extender cables 

„ Local peer bus extender cables 

„ Right 1-wide carrier with termination

Logic Solvers (SLS1508) contain the logic-solving capability and provide an interface to 16 I/O channels that can be configured as Discrete Input, Discrete Output, Analog Input (HART) and HART two-state output channels. Logic Solvers and termination blocks install on the 8-wide carrier. Logic Solvers communicate with each other through the carriers over a two-channel, local peer bus (SISnet) and remote peer ring. Local Logic Solvers are hosted by the same DeltaV controller and remote Logic Solvers are hosted by a different DeltaV controller. Logic Solvers are powered by a 24 V DC power supply that is separate from the power supply that drives the DeltaV controller and I/O. Logic Solvers install in odd-numbered slots (1,3,5,7) on the 8-wide carrier. Redundant Logic Solvers use four slots.

SISnet Repeaters extend communication beyond the local Logic Solvers connected to one DeltaV controller and broadcast global messages to remote Logic Solvers through a fiber-optic ring Carrier extender cables extend Local Bus power and signals between 8-wide carriers. Local peer bus extender cables extend the local peer bus (SISnet) between Logic Solvers on different carriers. 1-wide carriers with terminators terminate the local peer bus at the final carrier.

Communication

Control Network: The DeltaV Control Network provides communication between the nodes in the DeltaV network. Refer to the Installing Your DeltaV Digital Automation System manual for complete information on the Control Network.

Local Bus: The Local Bus provides communication between DeltaV controllers and Logic Solvers and between DeltaV controllers and SISnet Repeaters.

Local Peer Bus (SISnet): Logic Solvers communicate with other Logic Solvers and with local SISnet Repeaters through the carriers over a 2 channel local peer bus. The same message is broadcast over both channels. The local peer bus must be terminated at both ends. The local peer bus is terminated at the left end through the 2-wide power/controller carrier and at the right end through a terminated 1-wide carrier

Remote Peer Ring: SISnet Repeaters hosted by one DeltaV controller communicate with SISnet Repeaters hosted by a different DeltaV controller over a fiber-optic remote peer ring. A local SISnet Repeater collects locally generated messages that have been designated as global variables into a single message and sends it to the next SISnet Repeater in the ring. Upon receipt of a message, the receiving SISnet Repeater broadcasts it on its local peer bus (SISnet) and forwards the message to the next SISnet Repeater in the ring. A global message is forwarded around the ring once. The primary SISnet Repeaters form one fiber-optic ring and the secondary form a separate, independent ring.

Carrier extender cables and local peer bus extender cables connecting a DeltaV controller and 8-wide carrier with standard DeltaV I/O and DeltaV SIS Logic Solvers to a second 8-wide carrier (hosted by the same controller) are installed with Logic Solvers, SISnet Repeaters, and a terminated 1-wide carrier. Logic Solver messages are communicated to a remote DeltaV SIS (hosted by a separate controller) through fiber-optic cables.

Common Environmental Specifications for SLS 1508 Logic Solver

Number of Channels 16

Nominal Signal Span 4 to 20 mA 

Full Signal Range 1 to 24 mA