5 – Instruction Manual – Atrato Ultrasonic Flow Meter External Connections

Atato Ultrasonic Flowmeter EXTERNAL CONNECTIONS

Pin 6 (NPN):

ultrasonic flow meter external connections pin 6

Pin 6 can be configured as either an output or an input but not both simultaneously. If one input and one output is required the user must determine whether they require a NPN or PNP output and use the appropriate terminal for each action.


Pin 7 (PNP):

ultrasonic flow meter external connections pin 7

Pin 7 can be configured as either an output or an input but not both simultaneously.  If one input and one output is required the user must determine whether they require a NPN or PNP output and use the appropriate terminal for each action.  The options are – Not used Output Input .

Note: the operation for Pin 6 and Pin 7 are identical with the exception of the type of transistor output.

These instructions are the same for Pin 7 except the Pin 6 (PNP) would read Pin 7 (NPN).


Pin 6 (PNP)/PIN 7 (NPN)

The contents of this box will change depending on the selection made in the External connection box.

If Output is selected the check box options are:-

  • Pulse
  • Flow switch
  • Reverse flow

ultrasonic flow meter external connections pin 6a

Pulse: Enter the number of pulses per unit volume required.

This figure can be adjusted to suit the application and the flow range required from the meter.

The maximum output frequency is 400 Hz. So care must be taken to ensure that this pulse rate is not exceeded.

E.g. 10 L/Min at 400 Hertz equals (400 x 60)/10 = 2400

Therefore 2400 pulses per litre is the maximum resolution for 10 litres per minute assuming maximum frequency output.

If the meter is being used up to 5 L/Min the pulse output and so resolution could be doubled to 4800 P/L.

ultrasonic flow meter external connections pin 6b

Flow switch: The lower area of the section changes so that the user can enter the Threshold at which the transistor is to operate.

The Reset Offset (%): (Hysteresis) is either negative or positive depending on whether a falling or rising alarm is required.

This is to prevent output flutter if the flow is cycling around the set point value.
To reduce power consumption the transistor is off if positive hysteresis is selected and only powers when the threshold is exceeded.

If negative hysteresis is chosen the transistor is on up to the set point.

The increments are preset and can be cycled through using the + &- buttons.
If more than one set point is required either both transistors must be used or one transistor and the relay.

The right hand push button (or pin 7 set as an input) temporarily cancels the relay and resets the system.


EXTERNAL CONNECTIONS

If Input is selected either the left or right push button function can be operated remotely by using a switch and resistor to apply a suitable voltage (between 5 and 24 Vdc) to either Pin 6 or Pin 7 as described on page 11.

ultrasonic flow meter external connections pin 7


Notes on using electrical inputs to the Atrato Ultrasonic Flowmeter
Pin 6 : In input mode, the PNP open collector output is disabled,  and the input pin responds to an external input voltage at TTL levels (VinH ≥ 2.4V; VinL ≤ 0.8V).

This input must to be driven by an external voltage supply which can safely be in the  full range of zero to the external supply voltage. Because of the potential for conflict should the PNP output be activated accidentally,
Titan Enterprises Ltd recommend a resistor so that the sink current cannot exceed 5mA. An example circuit is given below:

ultrasonic flow meter external connections pin 6

Pin 7 : In input mode, the NPN open collector output is disabled, and the input pin responds to an external input voltage at TTL levels (VinH ≥ 2.4V; VinL ≤ 0.8V).

This input must to be driven by an external voltage supply which can safely be in the range of zero to 24V.

Because of the potential for conflict should the NPN output be activated accidentally,

Titan recommend a resistor so that the source current cannot exceed 5mA. An example circuit is given below:

ultrasonic flow meter external connections Pin 7


Atrato Ultrasonic Flowmeter Relay

RELAY MODE: If the relay is required for a flow switch check the flow switch box and a further set of options for set point and hysteresis will appear.

ultrasonic flow meter external connections relay

Threshold: Set the required flow rate for the flow switch.

The Reset Offset (%) (Hysteresis) is either negative or positive depending on whether a falling or rising alarm is required.

The relay has change over contacts but to reduce power consumption the relay is off if positive hysteresis is selected and only powers when the threshold is exceeded.

If negative hysteresis is chosen the relay is on up to the set point.
The increments are preset and can be cycled through using the + &- buttons.

If more than one set point is required either both transistors must be used or one transistor and the relay.


Analogue outputs

Analogue MODE: There are four options on the drop down menu:
Not Used, 4-20mA, 0-5 Volt and 0-10 Volt.
Once the selection has been made a further two boxes for entry of the analogue output at zero flow and full scale appear.
These are numeric entries in the units and time base selected earlier.

ultrasonic flow meter external connections analogue inputs


OUTPUT/DISPLAY DAMPING

Viewing filter: This prevents the display,
flow switches and analogue outputs from jittering with irregularities in the flow from say a peristaltic pump.
The increments are arbitrary with the degree of damping approximately doubling with each level.
Increments go up to F8, which may take up to a minute to stabilise.

ultrasonic flow meter external connections outputs

Real time view TAB: The large display reflects the meter readings showing on the Atrato LCD Display, if fitted and will mimic that display. The buttons either side have the functions selected on the ‘Configuration’ screen and
also work in parallel with the buttons on the Atrato flowmeter unit itself.
The small window below the rate and total display shows various relevant operational parameters whilst the unit is operating e.g.
relay status and frequency output if these options are selected; and overfill or under fill if in batch mode.

ultrasonic flow meter external connections interface control

FLOW RATE: This is the instantaneous flow rate and is updated approximately every 100 milliseconds.

Filtered Flow Rate: This is the filtered flow rate and is identical to the LCD display on the flowmeter (if fitted)
and the speed of change will depend on the filter setting.
The filter will also affect the response time for the analogue outputs and the flow switches.

TOTAL: The total liquid passed since the last reset.

PIN 6 & 7: If no selection is made “Not used” will be in the Notes column. See following text and chart for the display legends.

OR:- When Pin 6 or 7 is set to “Output” and set to “Pulse” this will
display the frequency of the running output and the number of pulses per litre selected.

OR:- If it is selected to “Output” and set to “Flow switch” the Value column
will show the transistor status either “low” or “high” and the notes will show the selected switch points.

OR:- If “Output” and “Reverse Flow” are selected the Value column will show either
“low” or “high” depending on forward or reverse flow.

OR:- If “Input” is selected the Value column will show “high” or “low” depending on the switch condition and “Input
Logic level” in the Notes column.


Calibration frequency

Checking this box gives a full scale output analogue voltage or current to check the system wiring and ancillary equipment.

To turn off this temporary output simply uncheck the box. No other changes can be made with this box open.

Real time view: The large display reflects the meter readings showing on the LCD display if fitted and will mimic that display.

The buttons either side have the functions selected in the System Configuration Settings  and also work in parallel with the buttons on the flowmeter LCD unit.

The small window below the rate and total display shows various relevant operational  parameters whilst the unit is operating e.g. relay status and frequency output if these  options are selected or in batch mode overfill or under fill.

FLOW RATE:

This is the instantaneous flow rate and is updated approximately every 100 milliseconds.

Filtered Flow Rate :

This is the filtered flow rate and is identical to the LCD display on the flowmeter (if fitted) and the  speed of change will depend on the filter setting.
The filter will also affect the response time for the analogue outputs and the flow switches.

TOTAL:

The total liquid passed since the last reset.

PIN 6 & 7:

If no selection is made “Not used” will be in the Notes column.
See following text and chart for the display legends.

OR:- When Pin 6 or 7 is set to “Output” and set to “Pulse” this will display
the frequency of the running output and the number of pulses per litre selected.

OR:- If it is selected to “Output” and set to “Flow switch” the Value column will show the  transistor status either “low” or “high” and the notes will show the selected switch points.

OR:- If “Output” and “Reverse Flow” are selected the Value column will
show either “low” or “high” depending on forward or reverse flow.

OR:- If “Input” is selected the Value column will show “high” or “low”
depending on the switch condition and “Input Logic
level” in the Notes column.

The chart below shows the message details for a variety of
configuration settings and meter running conditions.

PIN 7:

The display for “Pin 7” will function the same as “Pin 6” (see above).

Relay:

If no function is set for the relay the Value column will show “Off”
otherwise it will display the function and its operating parameters.

Batching option:

If Batch is selected in the “Display mode” the relay is automatically assigned to the total display for batching pre-set volumes of liquid.

The preset batch size can be entered in the relay box.

This value will be seen on the LCD display and will count down when the left hand start button is pressed.

The batch can be interrupted by pressing the right hand button, in the paused state a further press of the right button cancels the batch.

If you wish to continue the batch from the paused state the left hand button continues the dispense from the point it was interrupted.

If an alternative batch size is required after the unit is disconnected from the computer pressing both buttons together for 3 seconds  will permit the batch size to be altered by using the right hand key to increment the digit that is flashing and the left hand button to advance to the next digit.

Holding the left button for 3 seconds enters the selected numbers and the meter is ready to begin batching.

Both buttons can be operated remotely if required e.g. for remote start/stop signals.


TECHNICAL SPECIFICATION

The chart below shows the various display messages for various operating functions. During operation only one message will be shown for each parameter.

ultrasonic flow meter external connections - messages

PIN 7: The display for “Pin 7” will function the same as “Pin 6” (see page 13).

Relay: If no function is set for the relay the Value column will show “Off” otherwise it will display the function and its operating parameters.

Batching option: If Batch is selected in the “Display mode” the relay is automatically  assigned to the total display for batching pre-set volumes of liquid. The preset batch size can be entered in the relay box. This value will be seen on the LCD display and will count down when the left hand start button is
pressed. The batch can be interrupted by pressing the right hand button,
in the paused state a further press of the right button cancels the batch. If
you wish to continue the batch from the paused state the left hand button
continues the dispense from the point it was interrupted.

If an alternative batch size is required after the unit is disconnected from
the computer pressing both buttons together for 3 seconds will permit
the batch size to be altered by using the right hand key to increment the
digit that is flashing and the left hand button to advance to the next digit.
Holding the left button for 3 seconds enters the selected numbers and the
meter is ready to begin batching. Both buttons can be operated remotely
if required e.g. for remote start/stop signals.

ATRATO ADVANCED USER TAB

ultrasonic flow meter external connections advanced

PIN protection: This is for both the advanced and standard features.
Accumulated total: Accessible and resettable from both the front panel and
through the software.
Minimum flow cut-off: This is to ensure that inaccurate low flow measurements are not recorded or returned. This is normally set to the minimum flow for the meter.
Median filter: This is a filter that will remove short term erroneous flow
results.
Signal quality: The bar graph should be green, orange is a low signal quality
and red is very poor. This usually signifies gas break-out in the fluid or a system not fully bled.
PIN protection:
There are 2 possibilities for the PIN protection:-

To use these features it is first necessary to create a PIN. This is a four digit number in the range 0001 to 9999. Setting a value of 0000 tells the software there is no PIN and this is how to remove the PIN. After allocating a PIN these check boxes can lock all of the settings or just the advanced user, including the accumulated total reset. If you forget your PIN please contact you supplier for the default value. Once entered, all the setting parameters remain visible. In the ‘Help’ menu, the user can ‘Log On using PIN…’ but the user will be prompted for the PIN prior to making any changes. If the display version of the meter is being used and the display is set to view totals or rate and total
the left hand button will cycle through the various options.

  • Rate The display shows units and time base e.g. 1.0 Ltr/min.
  • Total The display is static with just the volume e.g. 10.3Ltr.
  • Accumulated total The display cycles “Ac tot” and the volume e.g. 120.3Ltr.

If the accumulated total is displayed and “right button resets totals” is selected in the configuration screen it can be reset by pressing both buttons simultaneously for 4 seconds. If PIN protection is selected the display will change to a flashing curser awaiting the pass word. The left button increments the value and the right button advances to the next digit. After all 4 numbers are entered pressing and holding the right key for 4 seconds resets the Accumulated Total. If a computer is being used for the reset simply press the “reset accumulated total” box.

Accumulated total DP position.
The chevron in the decimal point box calls a drop down selection showing the possible decimal point positions. Please ensure that the value selected has sufficient resolution for your anticipated accumulation period. This resets the accumulated total. If PIN protection is selected a PIN will be required.

Measurement control.
This sets the minimum flow for the meter. The default is the normal minimum under ideal conditions for the size of meter. This value can be adjusted to suit the operating conditions. e.g. If the automatic gain control is working hard with an attenuating (ultrasound absorbing) fluid the threshold of operation is automatically raised assuming that the background noise will also be higher. This may not be the case and the meter may perform reliably at a lower flow. One method of establishing a safe minimum flow is to set a low minimum cut off value with no flow and a full pipe. Check the totaliser or rate meter to see if any flow is being recorded if yes increase the minimum flow value and repeat until no flow is seen with zero flow in the pipe.

Median filter.
This filter removes short term anomalies in the recorded e.g. an air bubble passing through. It should be used with caution as it is theoretically possible that over use of this feature could lead to incorrect results in certain circumstances. Under normal operating conditions the meter returns around 25 results per second and a regular occurrence at this frequency could be completely ignored thus causing problematic readings. The filter is a moving window taking the middle number from an odd number of results selectable between 1 and 21. It is not an average or mean and it is designed to totally ignore one or more results. A simple example is shown on page 18 for a median value of “3”.

The seventh flow in the table above is zero. This could have been a small bubble passing through the 710 meter which has a 1mm bore which could completely absorb the ultrasound. The median filter completely ignores this reading and for the zero reading returns the value of 3 from the results either side. This filter is particularly useful at low flows where a small dip in value could drop a result below the internal cut off levels.