System Capacities

The following tables specify the capacity values of the DeltaV system. Refer to Batch System Capacities for batch-related capacity limits.

Inside this topic

Capacity Limits for System Topology
Capacity Limits for Workstations
Capacity Limits for Remote Networks and Workstations
Capacity Limits for Controllers
Capacity Limits for Remote I/O Nodes
Capacity Limits for SIS
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Capacity Limits for System Topology

Description of System Capacity

Limit

Control Network nodes 120
Total simplex and redundant controllers per control network (each redundant controller pair counts as a single node) 1001
Remote I/O nodes per control network 602
Workstations per Control Network
(non-remote)
60 workstations3 consisting of:

1 ProfessionalPLUS Station
Up to 10 Professional Stations
Up to 59 Operator, Maintenance and/or Base Stations
Up to 10 Application Stations (this is the supported limit)
Remote workstations (using Remote Access Services or RAS) per system 72 (10 on each of 7 Application Stations and 2 on the ProfessionalPLUS Station).
Application Stations set up as RAS servers 7
DeltaV Remote Clients
(using Windows Remote Desktop Connection and Terminal Server)
7200 graphic data links on all displays open through a terminal server4
60 database connections per terminal server5
15 concurrent sessions per terminal server6
Maximum number of client sessions (# of connections) attaching to an XP system
This affects any client retrieving information where the source of that information is on an XP workstation, including but not limited to: Process History View and Batch History View.
10
DSTs per system
 
30,000 DSTs distributed among controllers and Application Stations
SCADA tags per system 25,000
Maximum zones (including the current system) 10
Asset Manager Servers 50
1. This is a fixed system limit. The system does not permit the configuration of more than 100 controller nodes.
2. Additional -  not counted against Control Network nodes or controller nodes.
3. This is a fixed system limit. The system does not permit the configuration of more than 60 workstation nodes.
4. Graphic updates slow considerably when the total data links exceeds 7200. No warning message is given.
5. If the limit is reached, a message warns that the application can't connect to the database and it shuts down.
6. This is a tested limit, not a fixed limit. 

Capacity Limits for Workstations

Description of Workstation Capacity

Limit

For ProfessionalPLUS, Professional,
Operator, Maintenance and Base Stations
with Appropriate Licenses Installed
 
Total Unique Display links for systems using DeltaV Operate

The total includes: dynamic property links per display and
real-time trends per display. Data links typically count as one link.

<300
(recommended)

300 to 600
(performance degradation)

>600
(significant performance degradation)

>1000
(not supported)

Maximum open applications 30 (not all can be database connections)
Records per event chronicle 500,000
Maximum open DeltaV Explorer applications 1
Maximum open Control Studio applications 4
History values 250*
History sample rate per second (recommended) 2500
Open faceplates per module type 4
Open detail displays 1
Open pictures
 
30 (for proper operation, do not exceed 25.)
Workstation Object Identifiers 16,000
For the ProfessionalPLUS Station only  
Plant areas (including remote zone areas) 250
Modules per unit 255
Named sets 1000 (includes system enumeration sets. The number available to users is less.)
Alarm types 255
DeltaV user accounts per system 200
Parameters per security level 150
Maximum open engineering tasks on Professional Workstations
 
 
60 (includes applications open on local ProfessionalPLUS workstations)
Number of concurrent Professional Workstations connected 6
For Application Stations only
OPC data values 30,000
Maximum assigned modules 3,000
DSTs for Data Acquisition and Calculation Control 2,000
SCADA tags 25,000
History values (continuous historian) 30,250*
History sample rate per second (recommended) 2500
* The historians ability to record values is dependent on the number of values collected, the sampling period specified for those values and the workstation hardware. To ensure that all values are collected for the DeltaV Continuous Historian, configure the number of parameters and their sampling period such that the value of the HSLOAD diagnostics parameter in the historian subsystem remains below 100%.

For the Legacy Historian, the limit is 20,000 parameters. To ensure that all values are collected for the Legacy Historian, configure the number of parameters and their sampling period such that the value of the LOAD diagnostic parameter in the historian subsystem remains below 12%.


Capacity Limits for Remote Networks and Workstations

Description of Workstation Capacity

Fixed Limit

Remote workstations per ProfessionalPLUS (where the ProfessionalPLUS is acting as the Remote Access Server) 2*
 
 
Remote workstations per Remote Access Services (RAS) Application Station
 
 
 
 

 

10 total
*Additional remote workstations can access the ProfessionalPLUS for engineering data if they use another machine as their Remote Access Server.

Capacity Limits for Controllers

Description of Controllers Capacity

Limit

Fastest module scan time 100 ms
Simultaneous debug sessions 4
I/O cards per controller 64
DSTs per controller 750
Controller interfaced to PROVOX I/O - 750
Controller interfaced to RS3 I/O - 750
SCADA tags 3,200
Modules1 750
Nesting levels per control module 6
Controller free time minimum2 10%
Controller free memory3 400K
Unsolicited data reporting4 Controller and remote I/O node - 2000 exception reports per second
Maximum incoming unsolicited exception reports 250 per second
Maximum exception reports from one node to another node 750 per second
Write operations per node 20 per second
Minimum reporting rate Controller and remote I/O node- 500 ms
Controller Object Identifiers5 10,000
Virtual Control Object Identifiers5 16,000
Function Blocks per module 2506
1. The actual value might be less, depending on control strategy complexity.
2. Maintaining the free time above the recommended level ensures overhead to handle plant upsets, alarm bursts, and so on. Controller redundancy affects controller loading, as described below.
3. Maintaining the recommended amount of free memory ensures that modules can be applied to the controller through a partial download, in most cases. Some SFCs or other batch-related modules could require more than 400K of free memory to support partial downloads. For batch controllers, several megabytes may be required to support the configuration. Keep track of the value of the phase logic SIZE parameter and the value of the controller FREMEM parameter to ensure that there is enough memory.
4. Develop configurations using a recommended limit of 1000 parameters per second for the controller and remote I/O node. Exceeding these recommended limits may affect system performance.
5. The controller uses object identifiers to keep track of remote items such as modules with which it is communicating. Each connection with a remote item consumes one object identifier. Maintain the FreOID parameter value above 2000. A FreOID parameter value below 2000 may result in interrupted control and communication failure. If the FreOID value is low, you can increase it by decreasing the number of one or more of the following: the devices communicating with the controller, the modules from which the controller reads data, the modules running in the controller, and various I/O items (for example, assicated I/O cards, channels, datasets, ports, and so on).
6. The practical number of function blocks per module depends on a number of factors including configuration and associated I/O.

Controller redundancy has an impact on controller free time. Redundancy typically requires 20% more controller CPU than the same configuration in a simplex controller. Larger configurations require more CPU time for redundancy processing. A large configuration (for example, 300 modules) could require 25% or more of the controller CPU for redundancy processing. The loading estimation tool might not adequately account for redundancy CPU loading on systems with more than 150 modules. The controller loading estimation tool is included on the DeltaV installation disk #2 in the _Support\Tools\LoadEstimator folder.


Capacity Limits for Remote I/O Nodes

Description of System Capacity

Fixed Limit

Remote I/O cards per Zone 2 Remote I/O Node 8
Remote I/O cards per Zone 1 Remote I/O Node 4
Controller assignment per I/O card 1
Controller assignment per Remote I/O Node 4
Remote I/O Node assignment per controller 16
 


Capacity Limits for SIS

Description of Capacity

Limit

Application Limits  
Total function blocks per SIS module (including blocks in composites) 250*
Function blocks in the top level of a SIS module 127*
Function blocks per composite block 127*
Levels of composite nesting in a SIS module 1
Logic Solver Limits  
SIS modules in a Logic Solver 4
Secure parameters per Logic Solver 8
Logic Solvers per controllers 32 (simplex)
Logic Solvers that can publish data globally on one controller 8
Logic Solvers per system that can publish globally 32
Non-secure parameter references per logic solver 24
Temporary variables defined using VAR…END_VAR per expression 32
Workstation Limits  
Simulated Logic Solver Cards assigned to a ProfessionalPLUS workstation with Windows Server 2003 8
Simulated Logic Solver Cards assigned to a ProfessionalPLUS workstation with XP Professional 4
System Limits  
SISNet Repeater pairs in a DeltaV system 32
SISNet repeater rings in a system 1
Secure parameters published globally per system 256
Logic Solvers 1024
* The actual value may be less depending on a number of factors including: the complexity of SIS module configuration and the number and type of SIS function blocks used.