Endress+Hauser NXA820, NXA821, NXA822 Specifications

Technical Information

Tankvision NXA820, NXA821, NXA822

Inventory Management System
with completely integrated software
for operation via standard web browser

Application

Tankvision is a dedicated tank inventory system which is
operated by a standard web browser and does not require
proprietary software or licensing costs.

Tankvision is based on a distributed architecture on a
Local Area Network (LAN). Due to its modular structure
it can be adjusted to any application. It is ideally suited
for small tank farms with only a couple of tanks, but also
for large refineries with hundreds of tanks.

Tankvision consists of the following components:

• Tankvision NXA820 (Tank Scanner)
scans parameters from tank gauges and performs tank
calculations

• Tankvision NXA821 (Data Concentrator)
summarizes data from various Tank Scanners NXA820

• Tankvision NXA822 (Host Link)
provides data to host systems (such as PLC or DCS) via
Modbus

Your benefits

• License-free

• Approved for custody transfer applications according to NMI and PTB (in preparation)

• Global system engineering and service support

• A robust industrial operating system with embedded
software ensures high stability and availability.

• Modular design; easily adjustable to any application; can be upgraded as required

• Configuration, commissioning and operation via web browser; no proprietary software required

• Access for up to 10 users per Tankvision component from any connected PC

• Common hardware platform for all components; no hard disc or fans - no wearout

• Volume calculations and correction included
according to international standards (API/ASTM/IP
tables) in Tank Scanner NXA820

• Predefined or customized operator screens for typical operation of a tank farm

TI419F/00/en/05.08

Table of Contents

Tankvision NXA820, NXA821, NXA822

Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Inventory control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Inventory calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Remote configuration of measuring equipment . . . . . . . . . . . . . . . 3

Application areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Function and system design. . . . . . . . . . . . . . . . . . . . . 4

System design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

System configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Typical system configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Tankvision NXA820 (Tank Scanner) . . . . . . . . . . . . . . 7

Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Number of tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

LAN connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Input NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Output NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Power supply NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Terminals NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Ambient conditions NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Mechanical construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Human interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Certificates and approvals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Ordering information NXA820 . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Examples of operating pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Supplementary documentation . . . . . . . . . . . . . . . . . 40

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Description of Instrument Functions . . . . . . . . . . . . . . . . . . . . . . 40

Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

MODBUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Java . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Tankvision NXA821 (Data Concentrator) . . . . . . . . . 19

Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Number of tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

LAN connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Output NXA821 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Terminals NXA821 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Ambient conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Mechanical construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Human interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Certificates and approvals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Ordering information NXA821 . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Tankvision NXA822 (Host Link) . . . . . . . . . . . . . . . . 27

Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Number of tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

LAN connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Output NXA822 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Terminals NXA822 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Ambient conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Mechanical construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Human interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Certificates and approvals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Ordering information NXA822 . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Human interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Operating concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Languages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

System requirements

of user PC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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Tankvision NXA820, NXA821, NXA822

Applications

Inventory control By using Tankvision to monitor the tank level and stored volume of valuable liquids remotely, owners or

operators of tank farms or terminals for petroleum products and chemicals (liquids) can visualize the volume
of the stored medium in real time. The data can be used to plan the inventory and distribution. The data can
also be used to manage tank farm operations like pumping or transferring products.
Tankvision has its unique concept using network technology. Without using proprietary software, the users can
visualize and manage their valuable liquids stored in the tanks by a web browser.
Tankvision is a flexible and cost effective solution due to its scalable architecture. The application coverage goes
from small depots with only a few tanks up to refineries.

Inventory calculations Tankvision calculates gross, net volumes and mass, based on measured variables and tank capacity tables.

Volumes and density of products like hydrocarbons, LPG's, asphalt are corrected according to international
standards, including API/ASTM tables 5A, 5B/6, 53A, 53B/54, 23/24, LPG. This includes temperature
corrections at 15C, 60F and alternative temperatures. Additionally, available pumpable volumes and water
volume are calculated. Up to 3000 strapping points per tank are supported for vertical, spherical and bullet
tanks.

Remote configuration of measuring equipment

Application areas • tank farms in refineries

Tankvision does not only acquire the current measured level or volume from the tanks. The configuration of
device settings from the control room is also possible by using the corresponding HART operating software from
Endress+Hauser (e.g. ToF Tool or FieldCare) for the connected Endress+Hauser devices. Tankvision passes on
the device setting information transparently, so that all device functions for the respective operating software
are available from the control room. Some on-site operations can be avoided using this feature during
commissioning or maintenance. (The availability of this feature may depend on the system configuration.)

• ship loading terminals

• marketing and distribution terminals

• pipeline terminals

• logistic terminals for tanks storing products like crude oils, refined white and black products, chemicals,
LPGs

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Tankvision NXA820, NXA821, NXA822

Function and system design

System design Tank management visualization without proprietary software

Tankvision is the first tank management visualization system providing its functionality without the need to
have proprietary software installed and maintained on a PC. The main functionality is realized by embedded
web pages in the Tankvision components. Tankvision uses an industrial proven operating system and provides
high availability. Tankvision is not based on a PC platform and runs independent of connected PCs. This
eliminates the need to maintain a specialized PC with a Windows operating system and necessary updates and
hot fixes. Tankvision web pages can be accessed from a standard PC with a web browser and the Java Runtime
Environment only. Multiple users with different roles can simultaneously log in to each Tankvision component.
Additional users can be added as required. There are no multi-user licence fees.

Distributed architecture and scalability

Tankvision is based on a distributed architecture on a Local Area Network (LAN). Coordinated components
perform all inventory management tasks. The modular design makes it easy to enlarge the system whenever
required and to add further tank areas.
Thus, Tankvision is fully scalable and is ideally suited for applications of any size - from small tank farms to
large refineries.

Common hardware platform

The Tankvision components have dedicated tasks in a system, but have a common architecture, based on a 32
Bit processor. The embedded tank management software uses a multi-threaded real time operating system
(RTOS), specifically designed for industrial applications. The hardware is designed without wear-out
components like hard discs or fans. This guarantees high reliability.

System configuration Configuration of the components

Each Tankvision component has its own data base and a web server. The components are connected and
exchange data with time stamp and status information. Data is optionally encrypted and secured by a CRC
checksum.
The Tankvision components are configured with static IP addresses, which are reserved on a DHCP network.
The configuration pages are embedded in the Tankvision components and allow configuration of Tankvision
via a connected web browser without configuration software. No Internet access is necessary, as all pages are
loaded from the Tankvision system itself.

Configuration of the connected tank gauges/sensors
(available for Windows XP SP1; in preparation for Windows XP SP2)

Tankvision supports connection of Endress+Hauser configuration tools (e.g. ToF Tool or FieldCare) via LAN.
This enables configuration of the tank gauges if they support remote configuration (e.g. Tank Side Monitor
NRF590 and the level radars Micropilot S FMR53x/FMR54x).
The tank gauges must be connected to the Tank Scanner NXA820 in one of the following ways:

• via a field protocol

• via HART to the Tank Side Monitor NRF590 (version 02.04) which in turn is connected via one of the
following protocols to the Tank Scanner NXA820:
–MODBUS
–Sakura V1
– Whessoematic WM550 (in preparation)

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Tankvision NXA820, NXA821, NXA822

Features • Representation of tank data

Tank data can be represented graphically or in tables. The corresponding HTML pages are predefined.

• Definition and management of tank groups
The total contents of static or dynamic tank groups (e.g. of tanks containing the same product) can be
displayed.

• Definition and management of products
Product characteristics can be defined. The defined product can be attributed to a number of tanks. Links to
product safety sheets can be integrated.

• Trend display
Real time and historical trends of the tank parameters can be displayed. The data is stored in the internal
memory.

• Archive Tankvision stores measured and calculated data, log files and alarms on the internal flash memory.

• Alarms
Limit alarms (high-high, high, low, low-low) can be defined for measured and calculated tank parameters.
An alarm bar visualizes alarms in the browser window.
Alarms can be reported by an optional Alarm Popup

• Products A product database allows definition of 250 products per NXA or shared in the system.

• Monitoring of transfers
Product transfers from and to tanks can be monitored. Pre-alarms can be generated before completion of the
transfer. A report is issued after the transfer.

• Auditing An auditing table contains all events such as alarms or configuration changes.

• Log-In roles
Log-In roles with different access rights (supervisor, operator, guest) can be assigned to users and user
groups.

• Reports
Reports are predefined as HTML pages. They can be sent to a printer connected to a computer at scheduled
time intervals by an optional Printer Agent

• Volume calculation and correction Available calculation tables according to API, ASTM and IP can be integrated.

• Graphical User Interface (GUI)
Tankvision uses an intuitive and optimized user interface (e.g. automatic creation of dynamic tank groups).

• Remote access
Any PC with the specified requirements which is connected to the Intranet can be connected with
Tankvision.

• Redundancy (in preparation)
Two Tankvision components of the same type can be interconnected via the SyncLink interface. Only the
primary NXA has to be configured. The secondary NXA takes over the task if the master fails (see diagram
on page 6).

1)

window.

1

.

1) available for Windows on the device to upload; other operating systems in preparation

Endress+Hauser 5

Typical system configurations Small tank farm (up to 15 tanks)

NXA820

NXA820 NXA820

PLC

NXA822

NXA822
Host Link

FieldCare/

ToF Tool

Micropilot

Tankvision NXA820, NXA821, NXA822

Browser

Switch

NXA820

NXA820
Tank Scanner

Fieldbus protocol (e.g. MODBUS, V1, WM550*)

Prothermo

Prothermo

Proservo

Tank Side
Monitor

OPC Server

*in preparation

Promonitor

Refinery (up to 225 tanks)

DCS

(redundant) (redundant)

NXA820 NXA820

NXA820
Tank Scanner

NXA822

Host Link

NXA820

Tank Scanner

Data Concentrator

NXA820

NXA821

NXA820

Switch

Ethernet

NXA820

(redundant)

L00-NXA82xxx-02-00-00-en-001

Operator 1

Operator 2

Operator 3

NXA820

NXA820
Tank Scanner

Fieldbus protocol Fieldbus protocol Fieldbus protocol

L00-NXA82xxx-02-00-00-en-002

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Tankvision NXA820, NXA821, NXA822

Tankvision NXA820 (Tank Scanner)

Function • The Tank Scanner NXA820 connects multiple tank gauges from up to 15 tanks via one field-loop. The Tank

Scanner NXA820 supports different field protocols (Modbus EIA485, Sakura V1, Whessoematic WM550).

• The measured values are transmitted by the network and visualized on HTML pages.

• The Tank Scanner NXA820 can be used stand-alone for small tank farms, but also be integrated into a large
system for use in refineries.

• The Tank Scanner NXA820 is equipped with a full set of tank inventory calculations. The calculations are
based on various international standards such as API, ASTM, IP and many others. Measured values are used
to calculate volume and mass.

Number of tanks

LAN connections System LAN port

!

Protocol max. number of tanks per NXA820

MODBUS EIA485 15

Sakura V1 10

Whessoematic WM550 (in preparation)

100 BASE-TX, Full/Half Duplex, 100 Mbit, Shielded RJ45 connector Connects the NXA820 Tank Scanner to the Local Area Network (LAN)

Sync-Link LAN port (in preparation)

100 BASE-TX, Full/Half Duplex, 100 Mbit, Shielded RJ45 connector Connects the NXA820 Tank Scanner (e.g. primary) to an optional redundant unit (e.g secondary), to make sure the two devices remain synchronized with each other. If the primary unit fails, the secondary NXA820 Tank Scanner takes over operation without system interruption (see diagram on page 6).

Service LAN port

100 BASE-TX, Full/Half Duplex, 100 Mbit, Shielded RJ45 connector Connects the NXA820 Tank Scanner to a local computer only for local commissioning and service operations. The computer does not become part of the local area network the NXA820 Tank Scanner is connected to through the System LAN port. This port has a fixed IP address and can also provide the connected computer automatically with a compatible IP address using a DHCP server built into the NXA820 Tank Scanner. For this automatic IP function to work the computer must be set to obtain its IP address using a DHCP server

Note!
All LAN ports support Auto-MDIX. This system automatically detects the type of cable connected (either
straight or crossed) and adjusts itself to match. With this feature you do not need to obtain special crossed cables
to interconnect Tankvision components.

15

Input NXA820 Fieldbus protocols

The Tank Scanner NXA820 is available with the following field protocols:

• MODBUS EIA485 master, max. 15 gauges

• Sakura V1, max. 10 gauges

• Whessoematic 550, max. 15 gauges (in preparation)

Output NXA820 NXA Status Relay

• potential free relay, SPDT

• normally-closed when NXA is operating normally, open when NXA is powered off or in fault status

• switching power:
– 25 V
– 250 V

, 100 W

DC

, 4 A, 1000VA

AC

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Tankvision NXA820, NXA821, NXA822

Power supply NXA820

Instrument version Supply voltage Power consumption Current consumption Fuse

AC voltage NXA820 - ##1########

DC voltage
NXA820 - ##2########

90 - 250 V (50/60Hz)

10.5 - 32 V

AC

max. 23 VA max. 100 mA at 230 VAC 400 mA T

max. 14 W max. 580 mA at 24 VDC 2 A T

DC

Galvanic isolation

The following terminals are galvanically isolated from each other:

• Alarm relay output

• LAN interfaces

• Fieldbus interface

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Tankvision NXA820, NXA821, NXA822

Terminals NXA820

J K

I

321

E

RESET

L-

POWER

Fuse

2AT

10,5 ... 32V DC

231

6

7

8

NXAStatus

Relay

L+

F

RESET

10 11 12 13

MODBUS

6

7

W&M

8

D

10 11 12 13

E

G

L

H

L00-NXA82xxx-04-00-00-yy-019

A

B

C

A: Power supply; B: Fuse; C: Status relay; D: Fieldbus connection; E: Ground; F: System LAN port; G: Sync Link LAN port;
H: Service LAN port; I: Endress+Hauser CDI port; J: Display port; K: USB port; L: Weights & Measures locking switch

Power supply (AC version)

Terminal Meaning Remarks

1L

2N

3 Potential equalization

Fuse 400 mA T

90 - 250 V Connector: Phoenix 7.62 GMSTB/GFKC

AC

!

Power supply (DC version)

Terminal Meaning Remarks

1L+

2L-

10.5 - 32V Connector: Phoenix 7.62 GMSTB/GFKC

3 Potential equalization

Fuse 2 A T

Status Relay

Terminal Meaning Remarks

6 normally open contact

7 normally closed contact

8 switching contact

• NXA operating normally:
terminals 7 & 8 are interconnected

• NXA powered off or fault status condition: terminals 6 & 8 are interconnected

Connector: Phoenix FKC 2,5HC/3-St-5,08

Note!
The depicted switching state of the relay refers to the de-energized state.

DC

Endress+Hauser 9

Field connection: MODBUS Serial, EIA/TIA-485 (RS485)

Tankvision NXA820, NXA821, NXA822

Terminal EIA/TIA-485

13 S Capacitive Shield

12 C Signal Common

11 B + signal

10 A - signal

)

MODBUS

Ground Must be independently connected directly to a primary

Meaning Remarks

Connector: Phoenix FKIC 2,5/4-St-5,08

grounding point using 4 mm

2

cable.

Two-Wire MODBUS Definition

As described in the “MODBUS over serial line specification and implementation guide V1.02” published by the
Modbus-IDA organisation (www.modbus.org) and based upon the EIA/TIA-485-A physical layer specification.
MODBUS two-wire serial requires the following four electrical connections between each of the devices on
the bus:

Signal Purpose Remarks

A Data signal (-) These signals must be connected using a balanced twisted pair cable.

B Data signal (+)

C Signal Common Must interconnect all devices on the bus.

Shield EMC Protection Copper braided or combined foil and braided shielding.

Additional EIA/TIA-485 bus settings

• Bus biasing resistors (must be present at one point on the bus) (always enabled inside NXA820)

• Bus termination resistor (must be present at each end of the bus) (software selectable inside NXA820)

MODBUS Cable Specification

Characteristic impedance 135 to 165 Ω at measuring frequency of 3 to 20 MHz

Cable capacitance ≤ 30 pF/m

2

Core cross-section ≥ 0.34 mm

Cable type Single twisted pair + third conductor (for common)

or
Dual twisted pair (common uses second pair with wire joined together)

Cable resistance ≤ 110 Ω/km

Signal damping Max. 9 dB over the entire length of the cable cross-section

Shielding Copper braided shielding or combined foil and braided shielding

, corresponds to AWG 22, multi-strand cable is preferred

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Tankvision NXA820, NXA821, NXA822

Field connection: V1

Terminal V1 Meaning Remarks

)

V1 Definition

V1 fieldbus is a voltage mode digital communication using up to ±30 VDC, and requires the following three
electrical connections between each of the devices on the bus:

Signal Purpose Remarks

A Data signal (-) These signals must be connected using a balanced twisted pair cable.

B Data signal (+)

Shield EMC protection Copper braided or combined foil and braided shielding

13 S Capacitive Shield

12 Not connected

11 A - signal

10 B + signal

Ground

Connector: Phoenix FKIC 2,5/4-St-5,08

Must be independently connected directly to a primary grounding point using 4 mm

2

cable.

V1 Cable specification

Cable capacitance ≤ 50 nF/m

2

Core cross-section ≥ 0.9 mm

Cable type twisted pair

Cable resistance ≤ 30 Ω/km

Shielding Copper braided shielding or combined foil and braided shielding

Insulation ≥ 60 V

, corresponds to AWG 17, multi-strand cable is preferred

DC

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Tankvision NXA820, NXA821, NXA822

Field connection: Whessoematic 550 (WM550) (in preparation)

Terminal WM550 Meaning Remarks

13 Not connected

12 Not connected

11 + Loop Send

10 - Loop Return

)

Ground

WM550 Definition

WM550 fieldbus consists of a current loop which passes from the source device (e.g. NXA820) through all
connected gauges before returning to the source device. Typically this is managed by a single multi-core cable
which holds both the outgoing and returning current loop, and requires the following two electrical
connections between each of the devices on the bus:

Signal Purpose Remarks

+ Current Loop (+) Current always flows from positive to negative within the loop.

- Current Loop (-)

Connector: Phoenix FKIC 2,5/4-St-5,08

Must be independently connected directly to a primary grounding point using 4 mm

2

cable.

Caution!

"

WM550 loop signal voltages can be as high as 100 VDC.

WM550 Cable specification

Cable capacitance ≤ 75 nF/m

2

Core cross-section ≥ 0.5 mm

Cable type twisted pair

Cable resistance ≤ 40 Ω/km (total loop resistance ≤ 250Ω)

Shielding None

Insulation ≥ 100 V

, corresponds to AWG 20, multi-strand cable is preferred

DC

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Tankvision NXA820, NXA821, NXA822

Shielding and Grounding

When planning the shielding and grounding for a fieldbus system, there are three important points to consider:

• Electromagnetic compatibility (EMC)

• Explosion protection

• Safety of the personnel

To ensure the optimum electromagnetic compatibility of systems, it is important that the system components
and above all cables, which connect the components, are shielded and that no portion of the system is
unshielded. Ideally, the cable shields are connected to the normally metal housings of the connected field
devices. Since these are generally connected to the protective earth, the shield of the bus cable is grounded
many times. Keep the stripped and twisted lengths of cable shield to the terminals as short as possible.
This approach, which provides the best electromagnetic compatibility and personnel safety, can be used
without restriction in systems with good potential equalization.
In the case of systems without potential equalization, a power supply frequency (50/60 Hz) equalizing current
can flow between two grounding points which, in unfavourable cases, e.g. when it exceeds the permissible
shield current, may destroy the cable.
To suppress the low frequency equalizing currents on systems without potential equalization, it is therefore
recommended to connect the cable shield directly to the building ground (or protective earth) at one end only
and to use capacitive coupling to connect all other grounding points.

The NXA820 provides two grounding points for the shield, close to the fieldbus interface connector:

• The “)” terminal, which should already be connected directly to ground

• The “S” terminal (13), which provides capacitive connection to the “)” terminal

Caution!

"

The legal EMC requirements are fulfilled only when the cable shield is grounded on both sides!

Endress+Hauser 13

LAN connection

Socket Meaning Remarks

System LAN port Connects the instrument to the network.

Tankvision NXA820, NXA821, NXA822

Sync Link LAN port

(in preparation)

Service LAN port Connects the instrument to a computer locally for service purpose.

LEDs

Symbol Color Meaning

Green Power On

Yellow Stand-by

Indicates the box is a redundant secondary unit, and is ready to take over if the
primary unit fails.

Red Fault

Indicates a Fault when lit or "Maintenance required" when flashing

Yellow Communication

Flashes when the NXA820 Tank Scanner completes a successful fieldbus
communication cycle (e.g. Sent a request and received a reply).

Yellow Fieldbus Rx

Flashes to indicate data bits are being received from the connected field devices.

Yellow Fieldbus Tx

Flashes to indicate data bits are being sent to the connected field devices.

Data Transfer

Green Indicates data is being transferred on the LAN interface.

Yellow Indicates data is being transferred on the USB interface.

Green Linked

Used for connection to redundant unit.
If the primary unit fails, its task is taken over by the redundant unit.

Only this instrument can be configured. The Service LAN port does not
allow access to the network.

Yellow USB active (for future enhancements)

When lit the connected USB device has been detected and is in use. Do not remove
the device while this LED is lit.

Yellow Service

Indicates a Service operation is currently active (e.g. during HART tunnelling).

Additional elements in the terminal compartment

Symbol Meaning Remarks

Endress+Hauser CDI port Not used in the Tankvision instrument.

Display port For the connection of the local display in the housing cover.

Is connected on delivery.

USB port Reserved for future enhancements.

W&M

Weights & Measures Switch • :W&M parameters are unlocked and can be changed.

• :W&M parameters are locked and cannot be changed.

14 Endress+Hauser