Yokogawa 202 Field Mounting Rate Totalizer Uživatelský manuál

FIELD MOUNTEDRATE TOTALISERMODEL 202A 2 August 1999

2. SPECIFICATIONGeneralDisplay: LCD, which is continuously powered.Resettable Total: 7 digits with 10mm (0.4") high digits. Resettable from fron

OutputsType: Two open collector outputs suitable for driving DCsolenoids or external relays. The outputs provide highand low flow alarms or pulse out

3. PROGRAMMINGThe Model 202A is fully programmable, with all parameters being stored innon-volatile memory.The Program Mode can be entered in the foll

3.1 PROGRAM STEPSStep CommentCAL 00Pulse Output0 = No pulse output, low and high alarms1 = Scaled pulse output and low alarmCAL 01Span - whole number

Step CommentCAL 06Filter.Fluctuations in the flowrate can be filtered out so thatthe Rate is held steady. The filter value is programmedbetween 1 - 9

Step CommentCAL 11Low Alarm - digits after the decimal point.CAL 10 & 11 program the flowrate below which thelow alarm relay will close. The valu

3.2 CALCULATION OF RATE AND TOTAL3.2.1 Analog InputThe flowrate, R, is calculated as follows:R = SA if the linear relationship is selectedor R = S i

3.2.2 The Cutoff PointBecause many transducers do not always exactly transmit 4mA when they are atzero rate, it is often necessary to define a rate b

3.3 TOTAL CONVERSIONThe Total Conversion feature enables the rate to be displayed in one engineeringunit (eg. gallons/minute) and the totals to be di

3.4 FILTERINGFrequency fluctuations caused by pulsating flow through a flowmeter, oftenmakes the Rate impossible to read with any precision. The Mod

A 90% 99%1 0 02 1 24 2 46 3 610 5 1115 8 1720 11 2225 14 2835 20 4045 25 5160 34 6975 43 8690 52 10399 57 113Table 1 - Response to a step Input (in s

3.5 EXAMPLEA vortex flowmeter has a maximum output of 20.538 litres/min at 20mA. It isrequired to display the flowrate in litres/min with 1 decimal

4. SIGNAL INPUTThe signal input is on terminals 3 and 4 and can be connected as follows:20 Signal Input

5. ALARM & PULSE OUTPUTSOpen collector outputs are provided for high and low flowrate alarms. Theoutput can sink up to 200mA and can be used t

Connections22 Alarm & Pulse Outputs

6. INTRINSIC SAFETY CONNECTIONSWhen installing the Model 202A in hazardous areas, the wiring and installationmust comply with appropriate installat

24 Intrinsic Safety Connections

7. INSTALLATION7.1 WALL MOUNTINGA wall mounting bracket is supplied with each instrument. The bracket shouldbe attached to the wall using round head

7.2 PANEL MOUNT VERSIONThe panel mount version of the Model 202A is supplied with two panel mountbrackets and plug-in terminals which are accessible

7.3 REMOVING THE FRONT PANELThe front of the instrument is removed as follows:1. Remove both the top and bottom cover strips (ie. the dark plastic st

CONTENTS1. Introduction 31.1 Model Number Designation 4 1.2 Operation 61.3 Intrinsic Safety Considerations 7 2. Specification 83. Prog

28 Installation

7.4 THE MAIN ELECTRONICSThe front section of the housing contains the microprocessor and display.It is also possible to adjust the display contrast v

7.5 WIRINGWhen connecting the Model 202A, it is goods practice to use shielded cable.In order to comply with the requirements for Electromagnetic Com

7.6 TERMINAL DESIGNATIONS4-20mA Input3 4-20mA (-)4 4-20mA (+)Outputs5 Low Alarm (-)6 Low Alarm (+)7 High Alarm (-) or Pulse Output (-)8 High Alarm (+

Index AAccumulated Total, 6CCAL Sequences, 10Cutoff Point, 11DDecimal Point, 11Display, 8Display Test, 6FFiltering, 17HHi Test, 6High Alarm, 13IInstal

1. INTRODUCTION The Model 202A Rate-Totaliser is a microprocessor based instrument designed tomeasure a 4-20mA signal from flowmeters and pressure tra

1.1 MODEL NUMBER DESIGNATIONThe Model Number of an instrument describes which input and output optionsare installed.Model 202 A. 1 0 Input OptionsA

The Model 202AIntroduction 5

1.2 OPERATIONThe Model 202A Rate Totaliser will display:RateResettable TotalAccumulated Total.Both the Rate and Resettable Total are continuously dis

1.3 INTRINSIC SAFETY CONSIDERATIONSThe Model 202A is certified for use in hazardous areas and has both CENELECand CSA NRTL/C approvals.The Model 202A