Emerson DeltaV Controller Redundancy Function

Emerson DeltaV Controller

Core positioning and core advantages

The DeltaV controller redundancy function is applicable to M-series, S-series (including SZ type), and PK type controllers, aiming to avoid critical process interruptions and high downtime losses caused by controller hardware failures through the "primary backup controller" mode. The core advantages can be summarized as four key features:

Uninterrupted control operation: When the main controller fails, the backup controller automatically takes over without initialization or manual intervention. The on-site output signal is undisturbed and the process continues to run; No special wiring or additional configuration is required, redundancy can be achieved by simply adding controllers to the existing hardware foundation.

Online upgrade capability: Supports online upgrade of controller firmware and hardware. New firmware can be installed on the backup controller first (without affecting the current operation), and the backup controller will automatically configure and support switching after the upgrade is completed. After switching, the original main controller will be upgraded; At the hardware level, it supports online upgrades from MQ to MX and SQ to SX, meeting the requirements for expanding control strategies.

Automatic debugging and deployment: The system automatically detects, debugs, and downloads backup controller programs, making on-site equipment replacement safe and convenient; When adding redundancy, only a 2-slot backplane with system power supply needs to be installed for the M/Q/MX/SQ/SX controller. The SZ controller can directly use its 2 slots on the carrier, and the PK controller does not require an additional carrier (comes with 2 slots); No need to set up dip switches, jumpers or addresses, the backup controller automatically assigns addresses, the engineering database is automatically updated, and activation only requires assigning and downloading redundant licenses, without affecting the operation process.

Uninterrupted switching transition: When switching between primary and backup, the output channel remains in its current state until the switching is completed and the control module is started; The control module confirms that all I/O channels are normal through signal status before executing control actions, and uses the I/O read back function to synchronize output signals, ensuring that control calculations are based on real-time output status; This feature is suitable for scenarios where CHARM or DeltaV classic I/O cards are used, regardless of whether Foundation fieldbus devices are connected or not.

Product Core Function Details

（1） Working mechanism

The backup controller stores the same control strategy as the main controller, and redundant links transmit control parameters in real-time to ensure that the backup controller can take over at any time.

After enabling redundancy, each control module will calculate the required update data for the backup controller during execution and transmit it through the redundant link; Redundant functions typically reduce CPU idle time by about 10%.

After the fault triggers a switch, the DeltaV event recorder will store the switch record and the identified cause of the fault; Replacing the backup controller only requires disassembling and assembling the hardware, and the main controller will automatically detect the new backup device and complete debugging and program download.

（2） Switch detection logic

The main and backup controllers continuously self check and monitor each other, and the main controller runs a real-time self check program to determine the functional status.

Scenarios that trigger switching: hardware failure of the main controller, communication failure between the main controller and I/O, communication failure between the dual control network ports of the main controller, removal of the main controller from the carrier, and user switching requests initiated through a diagnostic browser.

If the main controller fails and does not initiate a switch, the backup controller will identify the abnormality by monitoring the I/O bus flow. Before switching, a verification cycle must be passed, during which all output signals remain unchanged until the new main controller starts the control strategy.

（3） System compatibility

Version requirements: The M/S/SZ series supports DeltaV v12.3 and above, while the PK series supports v14.3 and above; In the segmented models, SQ/SX requires v11.3.1+, SZ requires v12.3+, MX requires v10.3+, MQ requires v11.3.1+, and PK requires v14.3+.

Hardware pairing rule: Redundant controller pairs must be from the same series (e.g. M series and S series cannot be paired); Although SX can serve as a backup for SQ and MX can serve as a backup for MQ, it is recommended that the primary and backup hardware be consistent (low configuration primary controllers may not be able to support programs for high configuration controllers), and only temporary mixing during the upgrade period is recommended.

Supporting redundant controller models: MQ, MX, SQ, SX, PK (details can be found in the product manuals of each model), SZ (details can be found in the "DeltaV SIS Electronic Grouping" or "DeltaV SIS IS Electronic Grouping" manuals).