Micro Motion Signal Converter Owner's manual

Micro Motion

®

7950 Signal Converte

r

Operating Manual

MMI-20019471, Rev. AA

April 2011

7950 Signal Converter

(With Liquid Software 2010)

Introduction

:

The Micro Motion

®

7950 liquid signal converter can be used

for single-stream density and viscosity applications.

Software Version:

2010 – Liquid Density and Viscosity Applications.

Models Covered

:

7950MAA5*****

IMPORTANT NOTICE

Because we are continuously improving our products, some of the menus which appear on

your instrument’s display may not be exactly as illustrated and described in this manual.

However, because the menus are simple and intuitive, this should not cause any major

problems.

This manual is concurrent with embedded software version 502010, issue 2.81.

Static precautions

Some parts of the instrument (such as circuit boards) may be damaged by static electricity. Therefore, when

carrying out any work which involves the risk of static damage to the instrument, the instructions show the

following notice:

CAUTION

While carrying out this procedure, you must wear an earthed wrist strap at

all times to protect the instrument against static shock.

At such times you must wear an earthed wrist-strap to protect the instrument.

Safety information

NOTE: This information applies only to those instruments which are mains-powered.

Electricity is dangerous and you risk injury or death if you do not disconnect the power supplies before

carrying out some of the procedures given in this manual. Whenever there is such a hazard, the instructions

show a notice similar to the following:

WARNING

Electricity is dangerous and can kill.

Disconnect all power supplies before proceeding.

You must heed any such warnings and make sure that, before you go any further:

• All power leads are un-powered.

• All power leads are disconnected from the equipment which you are working on unless the

instructions tell you otherwise.

• You obey any other common-sense precautions which may apply to your situation.

If you obey these sensible precautions, you can work on the equipment in complete safety.

Battery-backed Memory notice

• It is essential that the Lithium Cell used for the battery backup is installed at all times (other than during

replacement). The 7950 Micro Motion

®

Signal Converter will not power-up correctly if this battery is missing.

If it is necessary to run the units without batteries for Intrinsic Safety reasons, then the battery should be

replaced with a shorting disk inserted in the battery holder. Please consult the factory for further advice.

• Replace the battery when the "Low Battery" system alarm is indicated. The procedure is in Chapter 14.

Contents

1. About this manual 1.1

1.1 What this manual tells you 1.1

1.2 Who should use this manual 1.1

1.3 Software version covered by this manual 1.1

2. Getting started 2.1

2.1 What this chapter tells you 2.1

2.2 What the examples show you 2.1

2.3 If you need help… 2.1

2.4 Example 1: 7950 with a 7826/35/45/46/47 densitometer 2.2

2.5 Example 2: 7950 with a 7827 viscometer 2.5

2.6 Output Connections 2.8

2.6.1 Relay Ouput 2.8

2.6.2 Digital (Status) Outputs 2.8

3. About the Micro Motion

®

7950 3.1

3.1 Background 3.1

3.2 What the 7950 Liquid Signal Converter does 3.1

3.3 Physical description of the 7950 3.2

3.4 Communications 3.3

3.5 Typical installations 3.4

3.6 Checking your software version 3.5

4. Installing the system 4.1

4.1 What this chapter tells you 4.1

4.2 Hazardous and non-hazardous environments 4.1

4.3 Installation procedure 4.1

4.4 Step 1: Drawing up a wiring schedule 4.1

4.5 Step 2: Unpacking the instrument 4.1

4.6 Step 3: Setting DIP switches 4.2

4.7 Step 4: Fitting the 7950 4.3

4.8 Step 5: Making the connections 4.3

4.9 Step 6: Earthing the instrument 4.4

4.10 Step 7: Connecting the power supply 4.5

5. The keyboard, display and indicators 5.1

5.1 What this chapter tells you 5.1

5.2 The layout of the front panel 5.1

5.3 What the display shows 5.2

5.4 How the buttons work 5.2

5.5 Using the buttons to move around the menus 5.2

5.6 Using the buttons to view stored data 5.3

5.7 Using the buttons to edit information 5.4

5.7.1 Text editing 5.4

5.7.2 Multiple-choice option selection 5.5

5.7.3 Numerical editing 5.5

5.7.4 Date and time editing 5.6

5.8 The 795x character set 5.7

5.9 LED indicators 5.7

5.10 Summary of key functions 5.8

6. The menu system 6.1

6.1 What this chapter tells you 6.1

6.2 What the menu system does 6.1

6.3 How the menu system works 6.1

7. Serial Communications and Networking 7.1

7.1 What this chapter tells you 7.1

7.2 7950 Communication capabilities 7.1

7.3 MODBUS from the 7950 point of view 7.1

7.4 Connecting the 7950 to A MODBUS network 7.3

7.4.1 RS-232 connections 7.3

7.4.2 RS-485 (half duplex) connections 7.4

7.5 Configuring the 7950 to be a MODBUS slave 7.6

7.5.1 Port configuration 7.6

7.5.2 High speed list configuration 7.7

7.6 Database access over a MODBUS network 7.8

7.6.1 Introduction 7.8

7.6.2 Database information type 1 : Data values 7.9

7.6.3 Database information type 2 : Data states 7.10

7.6.4 Database information type 3 : Reply size and type 7.11

7.7 Alarm logger access over a MODBUS network 7.12

7.8 High speed list access over a MODBUS network 7.15

8. Alarms and Events 8.1

8.1 Alarms

8.1.1 Alarm types

8.1

8.1.2 Alarm indicators 8.1

8.1.3 How alarms are received and stored 8.2

8.1.4 Examining the Status Display and Historical Log 8.2

8.1.5 What the Status Display tells you 8.3

8.1.6 What the entries in the Historical Log tell you 8.3

8.1.7 Clearing all entries in the Historical Alarm Log 8.4

8.1.8 User-defined alarms X and Y 8.5

8.1.9 User-defined ‘comparison’ limit alarm 8.6

8.1.10 Alarm Logger Output (ALO) 8.7

8.1.11 Alarm Message List 8.8

8.2 Events 8.9

8.2.1 Introduction to 795x events 8.9

8.2.2 Event indicators 8.9

8.2.3 How events are received and stored 8.9

8.2.4 Examining the Event Summary and the Event Log 8.10

8.2.5 What the Event Status Display tells you 8.10

8.2.6 What the entries in the Historical Event Log will tell you 8.11

8.2.7 Clearing all entries in the Historical Event Log 8.12

9. Additional facilities 9.1

9.1 What this chapter tells you 9.1

9.2 Averaging data 9.1

9.3 Selecting units and data formats 9.1

9.4 Limits 9.2

9.5 Fallback values and modes 9.2

9.6 Units which the 795x can display 9.3

9.7 Automated calibration procedures 9.4

9.7.1 Covimat - Static Zero Calibration (in air) 9.4

9.7.2 7827 Liquid Density Transducer 9.6

9.8 Feature: PID Control 9.8

9.8.1 Overview 9.8

9.8.2 Configuration details 9.9

9.8.3 Ramp-limit safeguard 9.11

9.8.4 Anti-Reset-Windup safeguard 9.12

10. Configuring with Wizards 10.1

10.1 Introduction to Wizards 10.1

10.2 Using Wizards 10.1

10.3 Quick-view Guide (Set-up Wizards) 10.3

10.4 Units Wizard Selection 10.4

11. Configuring without the Wizards 11.1

11.1 What does configuration involve? 11.1

11.2 Before you start 11.1

11.3 What will the sections tell you 11.1

11.4 Configuration Guide 11.2

11.5 Live Inputs

11.5

11.5.1 Analog Inputs 11.5

11.5.2 Time Period Inputs 11.6

11.6 Temperature Channels (A to K) 11.7

11.7 Pressure 11.8

11.8 Density 11.9

11.8.1 Transducer measured density 11.9

11.8.2 4x5 Matrix referred density 11.11

11.8.3 API referred density 11.13

11.8.4 Specific gravity 11.15

11.8.5 Degrees Brix 11.15

11.8.6 Degrees Baumé 11.16

11.8.7 Percent Mass 11.16

11.8.8 Percent Volume 11.17

11.8.9 Degrees Twaddell 11.17

11.8.10 Degrees API 11.18

11.8.11 Special Equation Type 1 11.19

11.9 Viscosity 11.21

11.9.1 7827 measured viscosity 11.21

11.9.2 Kinematic viscosity measurement 11.23

11.9.3 4x5 Matrix reference viscosity 11.24

11.9.4 ASTM D341 reference viscosity 11.26

11.9.5 Multi-curve ASTM reference viscosity 11.28

11.9.6 Ignition indexes 11.30

11.9.7 Saybolt Universal Viscosity 11.31

11.9.8 Saybolt Furol Viscosity 11.32

11.9.9 Special Equation Type 4 11.33

11.10 Interface Detection (Density/Viscosity zoning) 11.34

11.11 Custom Applications 11.35

11.11.1 Special Equation Type 2 11.35

11.11.2 General Constants 11.35

11.12 Live outputs 11.36

11.12.1 Analog Outputs 11.36

11.12.2 Information on Averaging and Filtering 11.37

11.13 Other Parameters 11.38

11.13.1 What the “Other parameters” option does 11.38

11.13.2 Passwords and security 11.39

11.13 Multiview 11.41

12. Routine operation (Data maps) 12.1

12.1 Viewing the data 12.1

12.2 Checking the performance of the 795x 12.3

12.3 Printed reports 12.5

12.4 Giving your 795x a tag number 12.6

13. Routine maintenance and fault-finding 13.1

13.1 Cleaning the instrument 13.1

13.2 Fault-finding 13.1

14. Removal and replacement of parts 14.1

14.1 Front panel assembly 14.1

14.2 Display 14.3

14.3 Connector board 14.4

14.4 Microprocessor board 14.5

14.5 Screen and RFI conductive strips 14.5

14.6 Terminal cover seal 14.7

14.7 Gland plate seal 14.8

14.8 Fuses 14.9

14.9 Back-up battery 14.10

15. Assembly drawing and parts list 15.1

15.1 What the drawing and parts list tells you 15.1

15.2 How to obtain spare parts 15.1

Appendices A.1

Appendix A Glossary A.1

Appendix B Blank wiring schedule B.1

Appendix C Technical data for the 7950 C.1

Appendix D Calculations and theory D.1

Chapter 1 About this manual

1. About this manual

1.1 What this manual tells you

This manual tells you how to install, configure, operate, and service the instrument. In addition, some information

is given to help you identify and correct some of the more common faults which may occur. However, since

repairs are done by changing suspected faulty assemblies, fault-finding to board component level is not covered.

This manual assumes that all devices or peripherals to be connected to the 795x have their own documentation

which tells you how to install and configure them. For this reason it is assumed that anything which you want to

link to the 795x is already installed and working correctly in accordance with the manufacturer’s instructions.

Since the instrument can be used for a wide variety of purposes, it is driven by software specially for your application.

This manual gives information about the software which applies to your machine only.

Throughout this manual the term '795x' is used to refer to all members of the 795x family (7950, 7951, and 7955).

1.2 Who should use this manual

This manual is for anyone who installs, uses, services or repairs the 795x.

1.3 Software version covered by this manual

The software version dealt with in this manual is given on the title page. Chapter 3 tells you about the software is

installed in your instrument.

Page 1.1

Chapter 1 About this manual

Page 1.2

Chapter 2 Getting started

2. Getting started

2.1 What this chapter tells you

If you are new to the 7950, the worked examples in this chapter can help you to become familiar with the

installation and configuration procedures. The examples are:

• 7950 with a 7826, 7835, 7845, 7846 or 7847 liquid density transducer (see page 2.2).

• 7950 with a 7827 viscometer (see page 2.5).

Work through whichever one is most like your installation. Section 2.6 provides details of connections required

for the relay output and the digital (status) outputs.

2.2 What the examples show you

Each example shows you how to:

• Wire up a simple system in a non-hazardous area.

• Set the DIP-switches inside the 7950.

• Find the menu from which you start configuration.

• Clear the memory of details of any existing configuration (OPTIONAL).

• Select the appropriate wizard to configure the simple system.

• Work through the wizard and input information.

• View the results of your configuration.

The examples do not give full instructions on how to fit and configure installations. They are intended purely to

give you confidence to install and configure your own equipment. Chapter 4 tells you how to make permanent

installations.

2.3 If you need help...

If you get into difficulties...

If you get into difficulties when using the wizards, you can abandon the configuration and start again as follows:

1. From the menu, keep selecting NO (usually by pressing the c-button) or, if that option is not available:

2. Press the ENTER button until you can start selecting NO.

3. Carry on with (1) and (2) until you return to the wizard selection menu where you started.

4. Start the worked example again. The configuration you abandoned is cleared from the instrument’s

memory when you begin again.

If you don’t know where the buttons are...

Chapter 5 gives a full explanation of what all the buttons do.

Page 2.1

Chapter 2 Getting started

2.4 Example 1: 7950 with a 7826/35/45/47 densitometer

About this example

This example shows you how to connect a 7826, 7835, 7845, or 7847 densitometer to the 7950, and then uses

the Liquid Density 1 wizard to configure the system. The Multi-view button can then be used to instantly display

the latest density and temperature readings.

In this example, the Liquid Density 1 wizard configures the connections as follows:

• The densitometer is connected to the Time Period Input 1 terminals.

• The PRT is connected to Analogue Input 1 terminals.

Work through the example by following the instructions below. Refer to Chapter 5 if you are not sure where the

buttons are.

Connect the

transducer

1. Wire the densitometer to the 7950 terminals, as in Figure 2.1 or Figure 2.2

2. To comply with EMC regulations, you must earth the 7950 to a suitable earth point.

Figure 2.1: Wired connections (7835, 7845, or 7847 with Standard Electronics)

Figure 2.2: Wired connections (7826 Frequency Output densitometer)

Page 2.2

Chapter 2 Getting started

Set DIP switches 3. Make sure that the DIP-switches are set as shown in Figure 2.3.

1

2

3

4

A

B

C

D

4-20mA

PRT

Figure 2.3: DIP-switch settings for Example 1

Turn on the power 4. Turn on the power to the system. The system goes through a Power-On-Self-Test (POST)

routine, which takes less than 30 seconds. When it is finished, ignore any flashing alarm

lights that may appear.

Go to the wizards

menu

5. Press the MENU button to go to Page 1 of the Main Menu (if you aren’t there already).

6. Press the DOWN-ARROW button to go to Page 2 of the menu.

7. Press the c-button to select “Configure”.

8. Press the a-button twice to go to the wizard selection menu.

Clear existing

configuration

(This is optional)

9. Press the b-button and then use the UP-ARROW or DOWN-ARROW button to scroll through

the option list until “Initialise” is shown.

10. Press the b-button to select “Initialise”.

11. Press the d-button to confirm that you want to lose the current configuration.

12. Wait a few seconds until “initialise” on display line 2 changes to “Select option”.

Select the wizard 13. Press the b-button then the UP-ARROW or DOWN-ARROW button to scroll through the

option list until “Liquid density 1” is shown.

14. Press the b-button to select “Liquid density 1”.

Start of wizard 15. Press the d-button to answer YES to the ‘Load Liquid density defaults?’ prompt.

Enter

densitometer

calibration factors

16. Press the d-button to answer YES to the ‘Edit density coefficients?’ prompt.

17. Press the b-button, then input the factor K0 from the Calibration Certificate for the

transducer. (See Figure 2.4 on page 2.4 for an illustration of the certificate).

18. Press the b-button followed by the ENTER button to confirm the K0 value.

19. Enter values for factors K1 and K2 in the same manner as factor K0.

Enter temperature

correction factors

20. Press the d-button to answer YES to the ‘Edit Liquid density correction?’ prompt.

21. Press ENTER button to keep the “Temperature” correction selected.

23. Enter values for factors K18 and K19 in the same manner as factor K0.

Skip questions 24. Use the c-button to answer NO to all further prompts until the Wizard is exited.

View how you

have configured

Line density

25. Press the MENU button.

26. Press the a-button twice. The display should now look similar to Figure 2.5, although the

values and text shown may vary.

View the Multi-

view display

27. Press the MULTI-VIEW DISPLAY button. The display looks similar to that in

Figure 2.6, although the text and values shown may vary.

End of Worked Example 1

Page 2.3

Chapter 2 Getting started

Figure 2.4: Where to obtain values for K0, K1, K18 and K19 from the Calibration Certificate

Line density

265.54

Kg/m3

Live

Figure 2.5: Line density display

Text width setting – a movable

boundary between text and value

Line dens 685.05

Ref Dens 0.000

Temp 29.5

Press 0.00

Text (e.g. parameter names)

Value of paramete

r

Figure 2.6: Multi-view display (after Liquid Density 1 wizard)

Page 2.4

Chapter 2 Getting started

2.5 Example 2: 7950 with a 7827 viscometer

About this example

This example shows you how to connect a 7827 viscometer to the 7950 and then uses the 7827 Density/Viscosity

wizard to configure the system. The Multi-view button can then be used to instantly display the latest viscosity,

density and temperature readings.

In this example, the 7827 Density/Viscosity wizard configures the connections as follows:

• The viscometer is connected to Time Period Input 3 terminals.

• The PRT is connected to Analogue Input 1 terminals.

Now work through the example by following the instructions below. If you are not sure where the buttons are,

refer to Chapter 5.

Connect the

transducer

1. Wire the 7827 viscometer to the 7950 terminals, as in Figure 2.7.

2. To comply with EMC regulations, you must earth the 7950 to a suitable earth point.

Set DIP

switches

3. Make sure that the DIP switches are set as shown in Figure 2.8.

Figure 2.7: Wired connections for 7827

1

2

3

4

A

B

C

D

4-20mA

PRT

Figure 2.8: Dip-switch settings for Example 2

Page 2.5

Chapter 2 Getting started

Turn on the power 4. Turn on the power to the system. The system goes through a Power-On-Self-Test (POST)

routine, which takes less than 30 seconds. When it is finished, ignore any flashing alarm

lights that may appear.

Go to the wizards

menu

5. Press the MAIN MENU button to go to Page 1 of the Main Menu (if you aren’t there already).

6. Press the DOWN-ARROW button to go to Page 2 of the menu.

7. Press the c-button to select “Configure”.

8. Press the a-button twice to go to the wizard selection menu.

Clear existing

configuration

(This is optional)

9. Press the b-button and then use the UP-ARROW or DOWN-ARROW button to scroll

through the option list until “Initialise” is shown.

10. Press the b-button to select “Initialise”.

11. Press the d-button to confirm that you want to lose the current configuration.

12. Wait a few seconds until “initialise” on display line 2 changes to “Select option”.

Select the wizard 13. Press the b-button then the UP-ARROW or DOWN-ARROW button to scroll through the

option list until “7827 dens/visc” is shown.

14. Press the b-button to select “7827 dens/visc”.

Start of wizard 15. Press the d-button to answer YES to the ‘Load 7827 viscosity defaults?’ prompt.

Find out the

viscosity ranges

for which the 7827

is calibrated.

16. The 7827 is calibrated for one or more of the viscosity ranges: High, Medium, Low or Ultra-

low. Check with the Calibration Certificate to see which ranges your instrument is

calibrated for. (See

Figure 2.9.)

Select the ranges

for which your

transducer is

calibrated

17. Press the d-button to answer YES to the question ‘Edit viscosity coefficient?’

18. Press the b-button, and then use the UP-ARROW button repeatedly until the display

shows the combination of viscosity ranges which applies to your 7827.

19. Press the b-button to select the option and then press the ENTER button to confirm that

you want to edit those viscosity ranges.

7827ACALMT VISCOMETER SERIAL NO

CAL DATE

PRESSURE TEST

: nnnnnn

: xxxxxxx

:nnBAR

VISCOSITY CALIBRATION @ nn C (T-piece)

O

VISCOSITY

(cP)

n

nn

nnn

nnnn

nnnnn

QUALITY

FACTOR

nnn.nn

nn.nn

VISCOSITY = V0 + V1.1/Q**2 + V2.1/Q**4

INSTRUMENT CHECK DATA

= nnnn

AIR POINT (nn C) QUALITY FACTOR

o

VISCOSITY CODE (for 7945V/6V) = nnnn

V0 =

V1 =

V2 =

DENSITY CALIBRATION @ nn C (T-piece)

O

DENSITY = K0 + K1.TB + K2.TB**2

K0 =

K1 =

K2 =

-n.nnnnnE+nn

n.nnnnnE-nn

DENSITY

(Kg/m)

3

n

n.n

nnn

nnnn

TIME PERIOD B

(usec)

nnn.nnn

nnn.nnn air check

nnn.nnn

Dt = D( 1 + K18(t-20) ) + K19(t-20)

K18 =

K19 =

-n.nnnE-nn

-n.nnnE+nn

VISCOSITY CORRECTION DATA

Dv = Dt + (K20 + K21.1/Q**2 + K22.1/Q**4)

MEDIUM RANGE

K20 =

K21 =

K22 =

-n.nnnnnE+nn

n.nnnnnE+nn

where

D = Density (uncorrected)

Dt = Density (temperature corrected)

Dv = Density (temp and viscosity corrected)

TB = Time period B (uS)

Q = Quality Factor

t = Temperature ( C)

o

FINAL TEST &

INSPECTION

Ref No:- xxnnnn/Vn.n

DATE : xxxxxxx

S

solartron

S

LOW RANGE

(n-nnn)

-n.nnnnnE+nn

n.nnnnnE+nn

MEDIUM RANGE

(nnn-nnnn)

-n.nnnnnE+nn

n.nnnnnE+nn

HIGH RANGE

(nnn-nnnnn)

n.nnnnnE+nn

ULTRA-LOW RANGE

(n-nnn)

-n.nnnnnE+nn

n.nnnnnE+nn

V0 =

V1 =

V2 =

LOW RANGE

(n-nnn)

-n.nnnnnE+nn

n.nnnnnE+nn

MEDIUM RANGE

(nnn-nnnn)

-n.nnnnnE+nn

n.nnnnnE+nn

HIGH RANGE

(nnn-nnnnn)

n.nnnnnE+nn

ULTRA-LOW RANGE

(n-nnn)

-n.nnnnnE+nn

n.nnnnnE+nn

DENSITY = K0 + K1.TB + K2.TB**2

K0 =

K1 =

K2 =

-n.nnnnnE+nn

n.nnnnnE-nn

Dt = D( 1 + K18(t-20) ) + K19(t-20)

K18 =

K19 =

-n.nnnE-nn

-n.nnnE+nn

Figure 2.9: Where to find values for V0, V1, V2, K0, K1, K2, K18 and K19 from the calibration certificate

Page 2.6

Chapter 2 Getting started

Enter the

calibration factors

for each viscosity

range

20. Repeat for each viscosity range (as selected in step 19):

• Press the b-button, and then input the factor V0 for the viscosity range.

• Press the b-button again, and then ENTER to confirm the details.

• Enter values for calibration factors V1 and V2 in the same manner as for V0.

• Press ENTER button to accept the default value (1.0) for the scale factor.

Enter density

calibration factors

21. Press the d-button to answer YES to the ‘Edit Density coefficient?’ prompt.

22. Press the b-button then enter the value for factor K0 from the Calibration Certificate.

23. Press the b-button and then press the ENTER button to accept the K0 value.

24. Enter values for factors K1 and K2 in the same manner as for factor K0.

Enter temperature

correction factors

25. Press the d-button to answer YES to ‘Edit Liquid density correction?’ prompt.

26. Press ENTER button to keep the “temperature” correction selection.

27. Enter the value for factors K18 and K19 in the manner as for factor K0.

Skip over the next

few questions

28. Press the c-button several times to answer NO to all questions until the wizard is exited

View Line

Dynamic viscosity

29. Press the MAIN MENU button.

30. Press the b-button and then the a-button. The display will look similar to that shown in

Figure 2.10, although the text and values shown may vary.

View Multi-view

display

31. Press the MULTI-VIEW DISPLAY button. The display will look similar to that shown in

Figure 2.11, although the text and values shown may vary.

End of Worked Example 2

Line dyn visc

1000

cP

Live

Figure 2.10: Line Dynamic Viscosity display

Text width setting – a movable

boundary between text and value

Dyn.Visc 1000.00

Kin.Visc 0.000

Dens 0.000

Temp 29.5

Text (e.g. parameter names)

Value of paramete

r

Figure 2.11: Multi-view display (after 7827 Density/Viscosity wizard)

Page 2.7

Chapter 2 Getting started

Page 2.8

2.6 Output Connections

2.6.1 Relay Output

There are 2 contacts:

1: “Normally Open” pin (PL5/1) or

“Normally Closed” pin (PL5/3)

2: “Common” pin (PL5/2).

This output functions as a ‘Watchdog’ for indicating the presence of at least one active alarm. For example, the

Normally Open (NO) contact is energised only if there is an alarm.

2.6.2 Digital (Status) Outputs

These outputs are of the open-drain type. Work through parts 1, 2 and 3 to understand all the physical

connections that need to be made to the 7950:

1. Power usage - external power (recommended)

External power supply provides

voltage and current suitable for

user selected relay.

Status output

7950

Status output common

0V from external power supply

This diode protects 7950

against reverse voltages

Figure 2.12: Wiring a Status Output

2. Status Output “Common” Pin

7950 Pin Comment

PL7/9 Use this pin for status outputs 2 to 4.

PL7/10 Use this pin for status outputs 5 to 8.

3. Status Output “Signal” Pin

Status O/P Default Function 7950 Pin

2 Limit Alarm Watchdog (ALO) PL7/2

3 Input Alarm Watchdog (ALO) PL7/3

Refer to Chapter 8 for information on alarm watchdog (ALO)

function. Status Outputs 4 to 8 are not used.

Chapter 3 About the Micro Motion

®

7950

3. About the Micro Motion

®

7950

3.1 Background

The Micro Motion

®

7950 was developed to meet the demand for a reliable, versatile, user-friendly and cost-

effective instrument for liquid and gas metering. It has a Motorola 68332 32-bit microprocessor and surface-

mounted circuit board components so that it is powerful, reliable and compact.

Features of the 7950 include:

• Simple access to information.

• Comprehensive interrogation facilities.

• Alarm and alarm history facilities.

• A menu-driven, user-friendly interface.

• NEMA 4X, IP65 enclosure.

• Dc powered.

• Three serial communication ports (using RS232 or RS485) for MODBUS communications and printing.

These facilities are described in more detail in the rest of this chapter.

3.2 What the 7950 liquid signal converter does

Utilising field transmitters and transducers, the 7950 will calculate:

• Line density.

• Line dynamic viscosity.

• Line kinematic viscosity.

• Temperature (A to K).

• Line pressure.

From these values the 7950 can derive:

• Matrix temperature referred density, corrected for pressure.

• API referred density.

• Saybolt universal viscosity (ASTM D2161).

• Saybolt viscosity at 122 deg.F.

• Saybolt viscosity at 210 deg.F.

• Referred viscosity (ASTM D341 equation, multi-curve ASTM or 4x5 Matrix).

• Ignition indexes CAII and CII.

Additional features:

• Interface detection - density or viscosity zoning

• PID Control

• User defined equations (Types 1, 2 and 4)

• Multi-view (display key)

• Analogue Outputs

• Security.

Page 3.1

Chapter 3 About the Micro Motion

®

7950

3.3 Physical description of the 7950

The 7950 is a wall-mounted instrument housed in a one-piece case. The upper part of the instrument has a

panel on which are mounted the keyboard and display. Below this, and stepped back slightly, is a terminal cover

which, when removed allows access to the electrical connectors on the connector board inside the instrument.

All wiring enters the case from underneath, through the gland plate which has to be drilled for the purpose.

The connector board is mounted vertically inside the back of the case. The microprocessor board is attached, by

six screws and stand-offs, to the back of the keyboard and display.

The upper and lower parts of the instrument are separated by a horizontal metal plate (the screen) which helps

to protect the instrument against electro-magnetic interference.

Figure 3.1: The 7950 and its major assemblies

Page 3.2

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Micro Motion Signal Converter Owner's manual

Micro Motion Signal Converter Owner's manual

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