Communicating with Daniel Ultrasonic Gas Flowmeter Model 3400, SeniorSonic

The Daniel SeniorSonic ultrasonic flowmeter determines the linear gas velocity through the meter tube by using multiple acoustic pulse paths. The flowmeter analyzes these paths by the delta time travel measurement method. The OMNI Flow Computer either totalizes the flowmeter pulse input signal or determines the flowrate from the data received from the flowmeter.

SeniorSonic Ultrasonic Flowmeter Theory of Operation

The Daniel ultrasonic gas flow-meter incorporates multiple pairs of transducers into a smart digital inferential instrumentation device. This device is installed into a gas pipeline system to measure gas flow. Each pair of transducers emits ultrasonic (acoustic) pulses that travel bi-directionally, to and from each transducer in the pair.

 

Four (4) pairs of transducers are positioned across the meter so that the path between each transducer has an axial component, i.e., one (1) transducer is upstream relative to the other. Pulses emitted by the downstream transducer are slowed down by the velocity of the fluid. With flow the pulse takes longer to travel to the upstream transducer than with no flow. Pulses emitted by the upstream transducer are aided by the velocity of the fluid. With flow the pulse takes less time to travel to the downstream transducer than with no flow. Ultrasonic flowmeters such as the SeniorSonic 3400 measure these two travel times to determine both the linear fluid velocity and the speed of sound in the fluid. The flowmeter can measure fluid velocity for bi-directional (forward/reverse) fluid flow.

OMNI Flow Computer Logic

The OMNI Flow Computer can determine the actual flow rate from data received either serially from the SeniorSonic flowmeter, or from a live pulse frequency signal input if one has been connected, assigned, and configured. To determine the actual flow rate, Modbus serial communication can be configured as the primary measurement source with the pulse frequency configured as the backup measurement source or vice versa. The OMNI Flow Computer can also be configured to use only the Modbus serial communication link with no pulse frequency input. When Modbus communications are available, the flow computer transmits flowing temperature and pressure to the flowmeter to enable it to correct spool dimensions.

 

The flowmeter serially transmits the accumulated volume to the OMNI. The flow computer obtains a calculated volume increment by subtracting the new accumulated volume from the last accumulated volume it received. The flowmeter updates its totalizers on a regular interval depending upon flowing conditions and configuration settings. Updating the OMNI totalizers on this same period would result in somewhat erratic totalizers and sampler pulse outputs, which could upset other equipment connected to the flow computer. The OMNI provides a smooth totalizer update by monitoring the time interval between SeniorSonic totalizer updates, and distributing the volume increment over a matching time-period (Figure 1).

 

Figure 1.  Daniel SeniorSonic 3400 Ultrasonic Gas Flowmeter

 

In the event of a communication failure between the two (2) devices, the OMNI will not receive serial data. However, the SeniorSonic may be fully operational and continue to accumulate volume. In this case, if a pulse signal is available from the flowmeter and the OMNI Flow Computer is configured to receive the flow pulse signal as a backup, the flow computer will automatically continue to accumulate flow based on this flow pulse train. When normal communications resume, the flow computer will validate and adjust its internal totalizers if necessary to match the SeniorSonic internal totalizer. The flow computer automatically adjusts its totalizers to account for the small amount of flow that takes place before it detects that a communication failure has occurred (i.e., the OMNI does not immediately start totalizing using the SeniorSonic pulse train).

 

If a pulse signal from the SeniorSonic is not available, and the communication link fails, the flow computer immediately stops totalizing. Once communication is reestablished, the OMNI will adjust its internal totalizers to match the SeniorSonic totalizer. In this case, the OMNI may have to add a significant amount of flow to its totalizers, depending upon how much time the communication link was inoperative.

 

In some instances, adjusting the flow computer’s totalizers may not be desirable; e.g. if a flowmeter has been disconnected for a long period of time, or the SeniorSonic electronics package has been replaced. For these cases, there are flow computer configuration settings that specify the maximum time that a SeniorSonic serial communication failure can exist, and still be compensated for by adjusting the flow computer totalizers. By default, this maximum time is fifteen (15) minutes.

Modbus Communication

NOTE:  The serial interface between these devices is 2-wire RS-485 mode utilizing a modified Modbus protocol.

The SeniorSonic connects to an external system using the Modbus ASCII protocol via a serial line. This connection is typically a 2-wire RS-485 serial link.  Communications parameters are fixed in the OMNI (Table 1):

 

Table 1.  Fixed Communications Parameters

Setting

Value

Baud Rate

9600

Data Bits

7

Stop Bits

1

Parity

Even

Protocol

Modbus ASCII

NOTE:  In order to communicate with Daniel Senior Sonic ultrasonic flowmeters, the OMNI Flow Computer must be equipped with at least one (1) SV combo module (Model 68-6203).  For instructions on jumper settings and other process I/O combination module setup information, refer to Volume 1, Chapter 2 of the OMNI User Manual.

Wiring Installation

There are several options for wiring a SeniorSonic ultrasonic meter to an OMNI Flow Computer.  The option to implement depends upon requirements of the flow metering system.

 

Always interconnect these devices via a 2-wire RS-485 serial interface from the SeniorSonic to an OMNI SV combo module serial port. This connection uses the Modbus protocol to transmit to the OMNI the volumetric flow data that the SeniorSonic accumulates. The OMNI also transmits the fluid temperature and pressure to the flowmeter to allow the flowmeter to correct for dimensional changes of the measurement Spool.

 

In addition to serial data, the OMNI can also receive live forward and/or reverse flow pulse signals from the SeniorSonic. The SeniorSonic transmits pulse frequencies through wires typically connected to an OMNI E combo module. Connecting two (2) SeniorSonic pulse output channels to the OMNI can provide pulse fidelity and integrity checking. To perform pulse fidelity checking, the OMNI must have one (1) E combo module for each flow direction requiring totalization.

OMNI Combo Module Terminal Assignments

Depending upon the implemented wiring option, the OMNI requires SV, E, and/or A combo modules. Tables 2 thru 4 specify the terminal assignments for each module type. This information is necessary when connecting wires to the OMNI. The terminal block number (TBn) on the OMNI back panel for each combo module corresponds to the slot on the motherboard into which the module is plugged. For more information, refer to “Volume 1: System Architecture and Installation” of the OMNI User Manual.

 

Table 2.  OMNI SV Combo Module Back Panel Terminal Assignments (TBn)

Terminal

Signal Description

1

Port # 1 (3): RS-485 B Wire

2

Port # 1 (3): RS-485 A Wire

3

Port # 2 (4): RS-485 B Wire

4

Port # 2 (4): RS-485 A Wire

5

Signal Return for 4-20mA Analog Outputs

6

Signal Return for 4-20mA Analog Outputs

7

Analog Output # 5: 4-20mA

8

Analog Output # 6: 4-20mA

9

Analog Output # 3: 4-20mA

10

Analog Output # 4: 4-20mA

11

Analog Output # 1: 4-20mA

12

Analog Output # 2: 4-20mA

Note:

Numbers in parenthesis “( )” refer to SV module 2 if installed.

 

Table 3.  OMNI E Combo Module Back Panel Terminal Assignments (TBn)

Terminal

Signal Description

1

Input Channel # 1: 1-5v, 4-20mA, RTD

2

Input Channel # 1: Isolated Signal Return

3

Input Channel # 2: 1-5v, 4-20mA, RTD

4

Input Channel # 2: Isolated Signal Return

5

Input Channel # 3: Flowmeter Pulses

6

Input Channel # 4: Flowmeter Pulses

7

Double Chronometry Detector Switch Input (Active Low)

8

RTD Excitation Current Source Output #2

9

RTD Excitation Current Source Output #1

10

Signal Return for Terminals 5, 6, 7, 8, 9, 11 & 12 (Internally connected to DC power return

11

Analog Output # 1: 4-20mA

12

Analog Output # 2: 4-20mA

 

Table 4.  OMNI A Combo Module Back Panel Terminal Assignments (TBn)

Terminal

Signal Description

1

Input Channel # 1: 1-5v, 4-20mA, RTD

2

Input Channel # 1: Isolated Signal Return

3

Input Channel # 2: 1-5v, 4-20mA, RTD

4

Input Channel # 2: Isolated Signal Return

5

Input Channel # 3: Flowmeter Pulses

6

Input Channel # 3: Isolated Signal Return

7

Input Channel # 4: Flowmeter Pulses

8

Input Channel # 4: Isolated Signal Return

9

RTD Excitation Current Source Output #1

10

Signal Return for Terminals 9, 11 & 12 (Internally connected to DC power return

11

Analog Output # 1: 4-20mA

12

Analog Output # 2: 4-20mA  or  RTD Excitation Current Source Output #2 (See JP12 Setting)

SeniorSonic 3400 Terminal Assignments

Using the two (2) P2 terminal blocks # 3-3400-017 in the Senior Sonic to connect to the OMNI, Tables 5 and 6 specify the terminal assignments for each of these terminal blocks. This information is necessary when connecting wires to the Senior Sonic.

NOTE: Users of this Meter Model MUST verify the revision level of the installed meter and refer to that revision’s Operations and Installation Manual supplied with the meter for the correct terminals required for meter frequency and serial wiring. The wiring terminals will vary for each revision level.

 

Table 5.  SeniorSonic 3400 Electronics Board Terminal Block P2 Assignments Board # 3-3400-017

Terminal

Signal Description

1

DIG GND (Negative)

2

DIG GND (Negative)

3

FREQ1A Fwd Flow Pulses (Positive)

4

FREQ1B Fwd Flow Fidelity Pulses (Positive)

5

FREQ2A Rev Flow Pulses  (Positive)

6

FREQ2B Rev Flow Fidelity Pulses  (Positive)

7

N/A

8

N/A

9

N/A

10

N/A

11

N/A

12

N/A

 

Table 6.  SeniorSonic Peripherals Terminal Block P2 Assignments

Terminal

Signal Description

12

Signal Ground

11

RS-485-  (Negative)

10

RS-485+ (Positive)

*9

Signal Ground

*8

RS-485-  (Negative)

*7

RS-485+ (Positive)

Note * 12, 11, and 10 are internally connected to 9, 8, and 7

Other SeniorSonic 3400 Terminal Assignments

Tables 7 and 8 specify the terminal assignments for the terminal block # 2-3-3400-421.

NOTE:  Users of this Meter Model MUST verify the Revision level of the installed Meter and refer to that revision’s Operations and Installation Manual supplied with the meter, for the correct terminals required for meter frequency and serial wiring. The wiring terminals will vary for each revision level.

 

Table 7 SeniorSonic 3400 Electronics Board Terminal Block J4 and J5 Assignments Board # 2-3-3400-421

Terminal

Signal Description

J4-1

DOUT1B

} To Flow Computer

J4-2

DOUT1A

J4-3

DOUT1A

J4-4

GND1

J4-5

GND1

J4-6

FOUT1B

 

 

 

J5-1

DOUT2B

} To Flow Computer

 

J5-2

DOUT2A

J5-3

GND2

J5-4

GND2

J5-5

FOUT2B

J5-6

DOUT2A

 

Table 8.  SeniorSonic Peripherals Terminal Block J6 Port A or J7 Port B Assignments

Terminal

RS232  Signal Description      RS485

1

RX

RX +

2

TX

RX -

3

COMM GND

COMM GND

4

RTS

RTS

5

CTS

CTS

Forward & Reverse Flow Signals

Figure 2 is a typical wiring installation between the Daniel SeniorSonic with P2 of the connection board # 3-3400-017 and an OMNI 6000 for serial data and both forward and reverse flow signals.  Figure 2, assume that the OMNI 6000 has an A module plugged into slot TB5, and an SV module in slot TB6.

 

Figure 2.  Daniel Senior Sonic 3400

Example of wiring a Daniel SeniorSonic 3400 ultrasonic flowmeter (Figure 2) to an OMNI 6000 Flow Computer with connections for serial data and live forward and reverse flow signals (without pulse fidelity and integrity checking).

Forward Flow Only with (Dual) Pulse Fidelity & Integrity Checking

Figure 3 is a typical wiring installation between the Daniel SeniorSonic with P2 of the connection board # 3-3400-017 and an OMNI 6000 for serial data and forward flow signals, with connections for pulse fidelity and integrity checking. In Figure 3, assume that the OMNI 6000 has an E module plugged into slot TB5, and an SV module in slot TB6.

 

Figure 3.  Daniel SeniorSonic 3400

Example of wiring a Daniel SeniorSonic 3400 ultrasonic flowmeter (Figure 3) to an OMNI 6000 Flow Computer with connections for serial data, live forward flow signal, and pulse fidelity and integrity checking.

Forward & Reverse Flow with (Dual) Pulse Fidelity & Integrity Checking

Figure 4 is a typical wiring installation between the SeniorSonic with P2 of the connection board # 3-3400-017 and an OMNI 6000 for serial data and both forward and reverse flow signals, with connections for pulse fidelity and integrity checking.  Figure 4 assumes that the OMNI 6000 has two (2) E modules in slots TB5 and TB6, and an SV module in slot TB7.

 

Figure 4.  Daniel SeniorSonic 3400

Example of wiring a Daniel SeniorSonic 3400 ultrasonic flowmeter (Figure 4) to an OMNI 6000 Flow Computer with connections for serial data, live forward reverse flow signals, pulse fidelity, and integrity checking.

OMNI Flow Computer Configuration

Use the flow computer’s front panel keypad to enter configuration settings unique to the SeniorSonic Flowmeter. The configuration settings that are specific to the SeniorSonic flowmeter are under Miscellaneous Setup, Configure Meter Run menu and the Meter Run Setup menu. Enter the miscellaneous configuration meter run settings first and then proceed to the meter run setup entries (Review Chapter 2 Flow Computer Configuration in Volume 3 of the OMNI User Manual, and the Technical Bulletin 960701 (52-0000-0001) Overview of OMNICOM Configuration PC Software).

Miscellaneous Configuration Meter Run Settings

The following miscellaneous configuration meter run settings correspond to the SeniorSonic ultrasonic gas flowmeter:

0 = Select Serial Data as primary flow.  This means that the SV serial communications data will be the primary and the pulse input channel, if assigned, will be used as a backup means of flow calculations by the flow computer.

1 = Select Pulse Input as primary flow. This means that the flow pulses received from the flowmeter will be the primary and the SV serial communications data will be used as a backup means of flow calculations by the flow computer.

Meter Run Setup Entries

NOTE: Difference Between ‘Gas Velocity’ and ‘Velocity of Sound’ – The ‘velocity of sound’ (VOS) refers to the amount of time it takes an acoustic pulse to travel along the gas ultrasonic paths. The VOS will vary depending upon gas type and line conditions

The following meter run setup entries are available for the SeniorSonic ultrasonic flowmeter when using pulse frequency signals:

NOTE: Daniel Industries recommends a minimum of sixty (60) minutes for this setting due to the fluctuating flow pulse frequency output by the flowmeter.

NOTE: Refer to the Flow Minutes setting previous.

OMNI Flow Computer Database Addresses & Index Numbers

Tables 9 thru 17 list the Modbus database addresses assigned within OMNI firmware to the SeniorSonic ultrasonic metering feature.  These tables categorize data type.

 

Table 9.  Meter Run Alarm Status Points – Real Time Data

 

Database Address

Description

For Meter Run Number

 

1

2

3

4

Loss of communication

2154

2254

2354

2454

Loss of pulse input

2155

2255

2355

2455

Flow rate deviation alarm

2156

2256

2356

2456

Path 0 Gas VOS alarm

2181

2281

2381

2481

Path 1 Gas VOS alarm

2182

2282

2382

2482

Path 2 Gas VOS alarm

2183

2283

2383

2483

Path 3 Gas VOS alarm

2184

2284

2384

2484

 

 

Table 10.  16-Bit Integer Register – Real Time Data

 

Database Address

Description

for Meter Run Number

 

1

2

3

4

Flow direction (0=frwd,1=rvrs)

3155

3255

3355

3455

 

Table 11.  32-Bit Integer Register – Real Time Data

 

Database Address

Description

for Meter Run Number

 

1

2

3

4

Volume From UFM (FWD)

15530

15630

15730

15830

Volume From UFM (REV)

15532

15632

15732

15832

 

NOTE:  Table 11 Modbus registors are available in 23.74.20 and later, 23.75.00 and later, 27.74.19 and later, and 27.75.00 and later.

Table 12.  32-Bit IEEE Floating Points – Real Time Data

 

Database Address

 

Database Address

Description

for Meter Run Number

Description

for Meter Run Number

 

1

2

3

4

 

1

2

3

4

Serial Gross flow during Flow Minutes period

17141

17151

17161

17171

Temperature

7105

7205

7305

7405

Pulses Gross flow during Flow Minutes period

17142

17152

17162

17172

Pressure

7106

7206

7306

7406

Calculated Flow Dev %

17143

17153

17163

17173

Velocity of sound A

17527

17627

17727

17827

Maximum flow deviation (%)

17513

17613

17713

17813

Velocity of sound B

17528

17628

17728

17828

Total from pulse input

17215

17219

17223

17227

Velocity of sound C

17529

17629

17729

17829

Dev % between serial & pulse

17216

17220

17224

17228

Velocity of sound D

17530

17630

17730

17830

Maximum VOS deviation (%)

17516

17616

17716

17816

 

 

Velocity of sound (VOS)

17521

17621

17721

17821

Gas velocity A

17533

17633

17733

17833

Gas velocity

17522

17622

17722

17822

Gas velocity B

17534

17634

17734

17834

 

Gas velocity C

17535

17635

17735

17835

Gas velocity D

17536

17636

17736

17836

 

Table 13.  32-Bit IEEE Floating Points Previous Hour’s Average Data

 

Database Address

Description

for Meter Run Number

 

1

2

3

4

Gas velocity A

17556

17656

17756

17856

Gas velocity B

17557

17657

17757

17857

Gas velocity C

17558

17658

17758

17858

Gas velocity D

17559

17659

17759

17859

 

Table 14.  32-Bit IEEE Floating Points Previous Hour’s Average Data

 

Database Address

Description

for Meter Run Number

 

1

2

3

4

Gas velocity A

17556

17656

17756

17856

Gas velocity B

17557

17657

17757

17857

Gas velocity C

17558

17658

17758

17858

Gas velocity D

17559

17659

17759

17859

 

Table 15.  32-bit IEEE Floating Points Previous Day’ Average Data

 

Database Address

Description

for Meter Run Number

 

1

2

3

4

Gas velocity A

17587

17687

17787

17887

Gas velocity B

17588

17688

17788

17888

Gas velocity C

17589

17689

17789

17889

Gas velocity D

17590

17690

17790

17890

 

Table 16.  Flow Computer Configuration Data – Miscellaneous Meter Run Configuration

 

Database Address

 

Database Address

Description

for Meter Run Number

Description

for Meter Run Number

 

1

2

3

4

 

1

2

3

4

Flow pulse I/O point #

13001

13014

13027

13040

DFI Retry Times

3156

3256

3356

3456

Flowmeter device type

3108

3208

3308

3408

Primary Flow

(0=Serial, 1=Pulses)

3157

3257

3357

3457

SV module port #

3153

3253

3353

3453

 

DFI Address

3154

3254

3354

3454

DFI Delay Timer

13445

13446

13447

13448

Flow direction (0=frwd,1=rvrs)

3155

3255

3355

3455

         

 

Table 17.  Flow Computer Configuration Data – Meter Run Setup

 

Database Address

 

Database Address

Description

for Meter Run Number

Description

for Meter Run Number

 

1

2

3

4

 

1

2

3

4

Meter maximum downtime (minutes)

3116

3216

3316

3416

Maximum VOS deviation (%)

17516

17616

17716

17816

 

Daniel Ultrasonic K-factor

17538

17638

17738

17838

Maximum flow deviation (%)

17513

17613

17713

17813

Minimum burst % 

17515

17615

17715

17815

OMNI Flow Computer User Displays

SV Module Serial Communications Port

You can view live data received via RS-485 communications on the flow computer front panel LCD display only if a SV port is used to input the RS-485 interface from the SeniorSonic flowmeter.  To view this data, press [Setup] [n] [Display] on the OMNI front panel keypad (where “n” equals the SV port number 1 to 4, you want to display), when in the Display Mode.  The following data will display (Figure 5):

 

Figure 5.  Display Mode

Meter Run Data

To view the meter run data on the flow computer LCD display, press [Meter] [n] [Display] on the OMNI front panel keypad (where “n” equals the meter run number, 1 to 4, you want to display), when in the Display Mode.  The following data will display: (Figure 6)

Figure 6.  Meter Run Data Display Mode

 

Technical Bulletin 020501