Contrec 102A User manual

MAN102A-V1.3
FIELD MOUNTED
RATE TOTALISER
MODEL 102A
APRIL 2019

MAN102A-V1.3

MAN102A-V1.3
CONTENTS
1. Introduction 1
1.1 Model Number Versions 2
1.2 Operation 3
2. Specification 4
3. Programming 6
3.1 Program Steps 7
3.2 Calculation of Rate and Total 10
3.3 Total Conversion 12
3.4 Filtering 13
3.5 Example 15
4. Signal Input 16
5. Alarm & Pulse Outputs 17
6. Installation 19
6.1 Wall Mounting 19
6.2 Removing the Front Panel 20
6.3 The Main Electronics 22
6.4 Wiring 23
6.5 Maintenance 23
6.6 Terminal Designations 23
7. Disposal
7.1 Instrument Disposal 24
Index 25

Introduction 1
MAN102A-V1.3
1. INTRODUCTION
The Model 102A Rate-Totaliser is a microprocessor based instrument designed to
measure a 4-20mA signal from flowmeters and pressure transducers. The
instrument can be programmed to display directly in engineering units and
includes features such as linear or square law calculation, integration and digital
filtering.
Rate, Total and Accumulated Total can be displayed in engineering units on the
large LCD display. A front panel switch selects the function for display and a Reset
button allows the Total to be reset to zero.
The instrument is fully programmable, with all calculation constants set via the
front panel switches and stored in a non-volatile memory which will retain data
indefinitely. The user can program span, filtering levels, display resolution and
cutoff point.
The instrument is powered from a 4-20mA input signal and therefore, requires no
external power.
The Model 102A Rate Totaliser conforms to the EMC-Directive of the Council of
European Communities 2014/30/EU, the LVD directive 2014/35/EU and the
following standards:
EN61326:2013 Electrical equipment for
measurement, control and
laboratory use –EMC requirements :
Residential, Commercial & Light
Industry Environment & Industrial
Environment.
EN61010:2010 Safety requirements for electrical
equipment for measurement,
control, and laboratory use.
In order to comply with these standards, the wiring instructions in Section 6.4
must be followed.

5 Introduction
MAN102A-V1.3
1.1 MODEL NUMBER VERSIONS
The Model Number describes the options available for the 102A as follows:
Model 102A . X
where x denotes the mounting options and will be replaced by one of the
following numbers:
2Wall mount (standard)
6 for Pipe mounting
The Wall mount instrument is supplied with cable glands that are watertight
and have integral strain relief.

Introduction 3
MAN102A-V1.3
1.2 OPERATION
The Model 102A Rate Totaliser will display:
Rate
Resettable Total
Accumulated Total
Both the Rate and Resettable Total are continuously displayed while the
Accumulated Total is only displayed when the ACCUM TOTAL key is pressed. The
Resettable Total can be reset at any time by pressing the RESET key.
The instrument also has a test mode which can be entered by simultaneously
pressing all three front panel keys. The tests are as follows:
Lo Test By pressing the ACCUM TOTAL key, the low alarm output will go
low.
Hi Test By pressing the RESET key, the high alarm output:
a. will go low if CAL00 = 0 (high alarm output),
b. will output 100ms pulses every 0.5sec if CAL00 = 1 (scaled
pulse output).
Display Test By pressing the PROGRAM key, all segments of the display will
show.
To exit the test mode, simultaneously press all three front panel keys.
Note that when the input signahil drops below 3.75mA (4-20mA input), a signal
error will occur. The display will alternate between the current total and the word
"SIGNAL". When the input signal drops below 3.5mA the Model 102A shuts
down saving totals in the non-volatile memory.

7 Specification
MAN102A-V1.3
2. SPECIFICATION
General
Display: LCD, which is continuously powered.
Resettable Total: 7 digits with 10mm (0.4") high digits.
Resettable from front panel.
Accumulated Total: Displayed when the Accumulated Total button is
pressed.
Rate/Display: 5 digits with 8.5mm (0.33") high digits.
Span: The units of measure per timebase (eg. gallons/sec) is
programmable in the range 0.000001 to 999,999.
Decimal Points: Decimal Point positions are fully programmable for
both rate and total.
Timebase: Span can be programmed in units per second, minute,
hour or day.
Signal Type: 4-20mA.
4-20mA Input
Resolution and
Linearity: 0.05% of span.
Accuracy:
0.1% (typ) of span, full temperature range.
Update Time: 0.5 seconds.
Connection: Two wire.
Voltage Drop: 2.5 volts maximum.

5 Specification
MAN102A-V1.3
Outputs
Type: Two open collector outputs suitable for driving DC
solenoids or external relays. The outputs provide high
and low flow alarms or pulse output and low flow
alarm.
Switching Power: 200mA. 30VDC maximum.
Saturation Voltage: 0.8VDC typical across the output in the "on" state.
Isolation: Both outputs are separately opto-isolated.
Pulse Duration: If CAL00 = 1 (scaled pulse output):
(for pulse output) a. 1ms if output frequency > 50Hz,
b. 10ms if output frequency is 5 ... 50Hz,
c. 100ms if output frequency is < 5Hz.
Physical
Temperature: Operating Temperature: -
Dimensions: 97mm (3.8") high x 150mm (5.9") wide x 41mm (1.6")
deep (cable glands not included).
Protection: Sealed to Nema 4x or IP67 standards.
Cable Entry: By cable glands.
Wall Mounting: Universal Mounting Bracket supplied as standard.
Pipe Mounting: A galvanised metal bracket is available which enables
the Model 102A to be attached to a 2" vertical or
horizontal pipe.

6 Programming
MAN102A-V1.3
3. PROGRAMMING
The Model 102A is fully programmable, with all parameters being stored in non-
volatile memory.
The Program Mode can be entered in the following way:
By removing the lower cover strip (ie. the dark grey strip along the bottom
of the enclosure) and replacing it the wrong side up. This brings a small
magnet on the inside of the cover strip in contact with a reed switch inside
the instrument.
The PROGRAM switch is used to step through the program (CAL sequences) and
the > and ˄keys on the front panel are used to change and increment the
flashing digits.
The CAL number is displayed on the lower display and the parameter is displayed
on the upper display.
Parameters in Program Mode that consist of the two parts, whole numbers and
digits after the decimal point, are restricted to having a maximum of 6 significant
digits. Therefore the number of significant digits entered in the whole numbers
determines the number of digits that are able to be entered in the digits after the
decimal point.
For Example
000001 in the whole numbers makes 00000 available after the decimal place.
000100 in the whole numbers makes 000 available after the decimal place.
010000 in the whole numbers makes 0 available after the decimal place.

Programming 7
MAN102A-V1.3
3.1 PROGRAM STEPS
Step
Comment
CAL 00
Pulse Output.
0 = No pulse output, low and high alarms
1 = Scaled pulse output and low alarm
CAL 01
Span - whole numbers.
CAL 02
Span - digits after the decimal point.
The Span is the number of units of measure per
timebase (eg. litres/sec, Gal/min). The Span can be
programmed in the range of 0.000001 - 999,999.
See section 3.2.
CAL 03
Cutoff Point.
This determines the cutoff point as a fraction of Span.
See section 3.2.2.
CAL 04
Decimal Point for Rate Display.
The flowrate can be displayed with 0, 1, 2 or 3 decimal
point places.
CAL 05
Timebase for Rate.
The Rate can be displayed in units per second, minute,
hour or day.
0 = second
1 = minute
2 = hour
3 = day.
See section 3.2.

8 Programming
MAN102A-V1.3
Step
Comment
CAL 06
Filter.
Fluctuations in the flowrate can be filtered out so that
the Rate is held steady. The filter value is programmed
between 1 - 99 where "1" represents no filtering and 99
is maximum.
See section 3.4.
CAL 07
Decimal Point for Total Display.
The totals can be displayed with 0, 1, 2 or 3 decimal
points.
CAL 08
Total Conversion Factor - whole numbers.
CAL 09
Total Conversion Factor - digits after the decimal point.
The Total Conversion Factor enables the Rate to be
displayed in one engineering unit and the Totals to be
displayed in another engineering unit. The Total
Conversion Factor can be programmed in the range of
0.000001 - 999,999.
Set to 1.000 if totals and rate are in the same unit eg.
litres.
See section 3.3.
CAL 10
Low Alarm - whole numbers.

Programming 9
MAN102A-V1.3
Step
Comment
CAL 11
Low Alarm - digits after the decimal point.
CAL 10 & 11 program the flowrate below which the low
alarm relay will close. The value can be programmed in
the range 0 to 999,999.
CAL 12
High Alarm or Pulse Output Factor - whole numbers.
CAL 13
High Alarm or Pulse Output Factor - digits after the decimal
point.
CAL 12 & 13 program the flowrate above which the high
alarm relay will close. The value can be programmed in
the range 0 to 999,999.
If the pulse output is selected (see CAL 00), the value
will represent the total per pulse. eg. 5 litres per pulse.
CAL 14
Input Flow Relationship.
0 = Linear Input
1 = Square Root Input
CAL 15
Accumulated Total Reset.
CAL 15 displays the accumulated total which can be
reset by pressing and holding the RESET key for about 5
seconds.
SOFT
Software Version.

Programming 10
MAN102A-V1.3
3.2 CALCULATION OF RATE AND TOTAL
3.2.1 Analog Input
The flowrate, R, is calculated as follows:
R = SA if the linear relationship is selected
or if a square law relationship is selected
where A = the input value
S = the span
At the minimum input (ie. 4mA), A = 0, and at the maximum input (ie. 20mA),
A = 1.
The Span, S, can be set during calibration anywhere in the range of 0.000001 to
999,999.
The Span, S, is programmed in units of volume per timebase (ie. litres/minute or
kilograms/hour). This also means that the Total will be displayed with the same
unit of volume, ie. litres or kilograms.
ASR 

Programming 11
MAN102A-V1.3
3.2.2 The Cutoff Point
Because many transducers do not always exactly transmit 4mA when they are at
zero rate, it is often necessary to define a rate below which no integration takes
place. This is termed the cutoff point and is programmed as a percentage of the
Span, S.
For example, if S = 2200 kg/min in a square law system, and the cutoff point is set
at 20.0%, the actual cutoff rate Rc can be determined as follows:
The cutoff rate is defined as:
At 20% cutoff,
Rc = 2200 x 0.2
= 440 kg/min
The value of A which would produce this cutoff is:
A = 0.04
and the input signal would be:
I = 16mA x 0.04 + 4mA
= 4.64mA
A2200Rc 
0.2)0.04(since 

Programming 12
MAN102A-V1.3
3.3 TOTAL CONVERSION
The Total Conversion feature enables the rate to be displayed in one engineering
unit (eg. gallons/minute) and the totals to be displayed in another engineering
unit (eg. barrels).
The Span is always programmed in the unit relating to Rate, and the Total
Conversion constant is a division factor which can be used to convert the totals to
the different unit. The Total Conversion factor affects the resettable and
accumulated totals.
For Example.
If the Rate is required in gallons per minute:
1. The Span would be programmed as gallons per minute.
2. The timebase would be programmed as minutes.
If the Totals are required in barrels:
3. The Total Conversion factor is programmed as 42 (there are 42
gallons in a barrel). All totals will now totalise in barrels.
Some common units are given below together with the Total Conversion constant
which should be programmed.
Rate* Totals TOTCON
Gallons (US)/ Barrels (oil) 42.000
Litres/ Kilolitres 1000
ml/ Litres 1000
Mgallons/ Acre-feet 0.32587
* Units per second, minute, hour or day. The timebase is programmed
separately during Programming.

Programming 13
MAN102A-V1.3
3.4 FILTERING
Frequency fluctuations caused by pulsating flow through a flowmeter, often
makes the Rate impossible to read with any precision.
The Model 102A has a digital filter which will average out these fluctuations and
enable the Rate to be read to four digit accuracy. The ability to select a suitable
filtering level means that highly accurate and stable readings can be obtained
without excessive lag.
The diagram below shows a pulsating signal input together with the effect of
filtering.
As a guideline to the degree of filtering to be used, the following table shows the
response to a step change in input. The value, CAL 06, is the filter constant which
is programmed during the Programming routine. The times for the display value
to reach 90% and 99% of full swing are given in seconds, for different values of
CAL 06.

14 Programming
MAN102A-V1.3
A
90%
99%
1
0
0
2
1
2
4
2
4
6
3
6
10
5
11
15
8
17
20
11
22
25
14
28
35
20
40
45
25
51
60
34
69
75
43
86
90
52
103
99
57
113
Table 1 - Response to a step Input (in seconds).
Note that if CAL 06 is set to 01 there is no filtering of the input signal.

Programming 15
MAN102A-V1.3
3.5 EXAMPLE
A vortex flowmeter has a maximum output of 20.538 litres/min at 20mA. It is
required to display the flowrate in litres/min with 1 decimal point and the total in
litres with no decimals. High and low alarms are required at 18 l/m and 2 l/m
respectively. The instrument is then programmed as follows:
CAL00
0
No Pulse Output
CAL01
00020
Span (Whole Numbers)
CAL02
5380
Span (Decimals)
03
0.05
Cutoff Point as a fraction of Span
04
1
Rate decimal position
05
1
Timebase
06
01
Filter disabled
07
0
Total decimal position
08
0001
Total Conversion (set to 1.0000)
09
0000
Total Conversion (decimals)
10
00002
Low Alarm
11
0000
Low Alarm
12
00018
High Alarm
13
0000
High Alarm
14
0
Linear Input
15
xxxx
Accumulated Totals
SOFT
202A1.12
Software Version

16 Signal Input
MAN102A-V1.3
4. SIGNAL INPUT
The signal input is on terminals 3 and 4 and can be connected as follows:

Alarm & Pulse Outputs 17
MAN102A-V1.3
5. ALARM & PULSE OUTPUTS
Open collector outputs are provided for high and low flowrate alarms. The output
can sink up to 200mA and can be used to power external relays, lights or audible
alarms. The outputs are internally protected against voltage spikes caused by
relays and coils.
Both outputs are separately isolated via opto isolators.
As an alternative to a high flowrate alarm, the output on terminals 7 and 8 can be
programmed to output a scaled pulse output.
The switching points can be programmed during the setup mode and the low flow
alarm will switch on whenever the flowrate drops below the programmed
flowrate. Similarly, the high alarm switches on whenever the flow exceeds the
high set-point.
If a Scaled Pulse Output is programmed, a pulse will be output every preset value
of the total. For example, if the total is in litres, then programming 5 will output
one pulse every 5 litres. The duration of pulses is adjusted automatically to the
output frequency.
Specification for Alarm Outputs
Maximum Current (sink): 200mA.
Maximum Voltage: 30VDC.
Saturation Voltage: 0.8VDC across Outputs when in the "on" state.
Isolation: Both outputs are separately isolated.
Pulse Frequency: 500Hz maximum.
Pulse Duration: 1ms if output frequency > 50Hz.
10ms if output frequency = 5 ... 50Hz.
100ms if output frequency < 5Hz.