Overview. Rosemount Smart Wireless Gateway

Reference Manual

00809-0200-4420, Rev HB

Appendix C DeltaV ™ Ready

C.1

C.2

C.3

Appendix C: DeltaV Ready

January 2015

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 63

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 63

Mounting and connecting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 64

Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 64

Overview

Native integration with DeltaV enables the Smart Wireless Gateway to be autosensed and easily commissioned for seamless integration with all DeltaV applications: Explorer, Diagnostics, and

Control Studio. WirelessHART ® devices can be easily added to the wireless field network and then reconciled through DeltaV Explorer and assigned to analog channels through drag and drop assignment.

Latency considerations in control logic design and operation

Since the DeltaV wireless I/O scanner software requests updates for 1/5 of the devices each second, DeltaV receives updates on a particular field device once every 5 seconds. That is not necessarily synchronized with the update rate of the field device. Also, there is some latency between when the field device takes a process sample and when it is permitted to pass its value onto the wireless network. Status update responses can also increase latency in some instances.

So for example, if a device updates once every 8 seconds, and wireless network latency is 2 seconds, the amount of time that could pass between when an event occurred in the field and before it is available to the DeltaV I/O bus is between zero and 15 (8+2+5) seconds. The update period of the DeltaV control module should be added to that total to determine the range of latencies before an event in the field can be acted upon by the control system.

Operators should be made aware that the update rate of wireless measurements on operator screens are somewhat slower than those from wired devices. For example, if the operator initiates a valve movement, it can be 5-15 seconds before confirming feedback appears on the operator screen. Any control logic designed along the same principles should also take the update rates and latencies into account as well.

Requirements

DeltaV

Version 10.3 or newer.

Smart Wireless Gateway

DeltaV Ready option (Data Protocol option 5). See

“Ordering information” on page 57

.

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