Overview
The 405 Flow Computer can handle a wide range of flow applications, where high accuracy and flexibility are required. It will interface to most flowmeters and versions are available for pulse and analog inputs.
Either the Flow Rate or a Resettable Total can be continuously displayed in engineering units on the large six digit LCD display. A non-resettable Accumulated Total is also displayed whenever the DISPLAY key is pressed.
A scaled pulse output, suitable for driving remote totalisers is a standard feature and the instrument also provides an 8-24 Volts dc power supply for driving transducers.
RS232 and RS422/485 communications interface
Optional features include: an isolated 4-20mA output; a communications interface; and high/low flow rate alarms which are output on two Form C relays.
The communications option includes both RS232 and RS422/485 interfaces for communicating with a computer.
Software drivers are also included for a number of printers and can print a ticket with time and date, a sequential ticket number, and the resettable and accumulated totals.
Set-up data is stored in non- volatile memory
The 405 is initially set-up by following a calibration sequence that enables scaling factors, digital filtering and display formatting to be set and stored in a non-volatile memory which does not require battery backup.
The instrument will operate from 12 to 28V dc or from the 110/220V ac mains.
Each flow computer is supplied with a sheet of self-adhesive engineering unit labels. A recess, adjacent to the display, is provided in which the correct label can be placed.
Features at a glance
- Large LCD display
- Operates from 12-28V dc or ac mains
- Scaled pulse output
- Accepts 4-20mA and frequency flow inputs
- Provides 8-24V dc transducer power
- High accuracy
- Self-adhesive engineering unit labels
- Simplified programming
- CE Compliant
Functions
- Rate
- Total (Resettable)
- Accumulated Total
Options
- 4-20mA isolated output
- RS232 and RS422/485 communications interface
- High/low alarm outputs
Digital filtering enhances Rate accuracy
Frequency fluctuations caused by pulsating flow through a flowmeter, often makes the Rate impossible to read with any precision.
The 405 has a digital filter which will average out these fluctuations and enable the Rate to be read to a four digit accuracy.
The degree of filtering is fully programmable which means that highly accurate and stable readings can be obtained without excessive lag.
Different mounting options available
The 405 is designed for panel mounting with the facia watertight to IP65 (Nema 4X) and resistant to most chemicals. A field enclosure and an explosion- proof enclosure are optionally available.
Models Available
Model 405A
An analog version with a fully isolated input. Inputs include 4-20mA, 0-20mA, 1-5V and 0-10V signals from flowmeters and pressure transducers. In addition to linear and square law input relationships, open channel applications can be handled via a programmable power on the input relationship.
Model 405B
A frequency input version that will accept pulse inputs and open collector inputs from opto-sensors or Hall effect devices.
Model 405D
Frequency input version with an input conditioning card capable of accepting mV signals from coils, two wire proximity sensors, reed switch inputs and most other pulse type signals.
Model 405LA
4-20mA temperature input version with temperature correction for general chemicals, LPG and petroleums to API tables (see separate data sheet on 405L and 414L).
Model 405LR
RTD temperature input version with temperature correction for general chemicals, LPG and petroleums to API tables (see separate data sheet on 405L and 414L).
Model 405Q
Frequency or pulse input with non- linearity correction and quadrature signal for measurement of bi-directional flows. The 405Q is highly suited to custody transfer applications where high accuracy and signal integrity is required.
Model 405S
For applications requiring the addition or subtraction of two flows this instrument will accept two frequency inputs and display Rate and Total for each channel.
Operation
The display of the 405 will normally show the Rate or Resettable Total (Net Total in the case of the 405LA, 405LR and 405S), as selected by the RATE orTOTAL keys on the keypad. An LED in the facia will indicate which function is currently displayed.
The DISPLAY key can be used to display the Accumulated Total. On the first press of the DISPLAY key, the display shows ACCTOT for one second followed by the actual total.
The Accumulated Total continuously totalises the flow and is not resettable via the front panel.
On reaching the maximum displayed total, all totals will roll over to zero and continue totalising. If, at any time, power is lost or the instrument is switched off, the totals will be stored in the non-volatile memory. When power is switched back on to the instrument, the stored totals will be recalled from memory and the totals will be incremented from the last values.
In the case of the Models 405LA and 405LR, if temperature compensation is selected, a second press of the DISPLAY key will show the product temperature or density if a density meter input is selected. A third press of the DISPLAY will show the actual Gross Total.
With the 405S, the first press of the DISPLAY key will show RATE 1, and the second press TOTAL 1, for input 1. The third press will show RATE 2, and the fourth press TOTAL 2, for input 2.
Specifications
General
Display
6 digit 0.7” (17.8mm) high LCD
Display Update Rate
0.25s. (0.5s on 405A)
Data Retention
Set-up parameters and totals stored in non-volatile memory with 10 years retention
Decimal Points
The number of decimal points with which the rate and totals are displayed can be programmed
Total Conversion
It is possible to program a constant so that the rate can be displayed in one unit (eg. gal/m) and the total displayed with a different unit (eg. barrels)
Time Base
The rate can be displayed in units per second, minutes, hours or days
Transducer Supply
8-24V dc field adjustable, 50mA maximum
Power Requirements
dc Supply:
11.5-28.5V dc, 130mA typical current (no options)
ac Supply:
ac mains set internally to 95-135V ac or 190-260V ac
Operating Temperature
0 to 55ºC
Rear Connection
Terminal Block
Front Panel
Material:
Polycarbonate
Protection:
IP65 (Nema 4X)
Case:
Aluminium
Inputs
Analog Input (405A)
Type:
Isolated 4-20mA, 0-20mA, 1-5V and 0-10V
Input Impedance:
Current 250 ohms
Voltage 10k ohms
Accuracy 0.075%
Span:
0.1000 to 50,000
Zero:
0.00000 to 50,000
Cut-off Point:
A low flow rate cut-off can be programmed below which flow is not registered. The cut-off is programmed as a percentage of span
Relationship:
Linear, square root or programmable
Open Channel:
For open channel flowmeters the power of the input relationship is programmable between 0 and 9.99. With open channel selected, the polarity of the signal can also be programmed such that, 20mA represents maximum or minimum flow
Frequency (Pulse) Input
(405B, 405D, 405Q and 405S )
Minimum:
0Hz on Totals, 0.25Hz on Rate
Maximum:
10kHz for single input, 2.5 for quadrature
Input Circuits:
Will accept most sine logic and proximity switch inputs
Scaling Range:
0.1000 to 50,000
4-20mA Inputs
(Flow and Temperature in the Model 405LA – see separate data sheet.)
RTD Input
(Model 405LR – see separate data sheet.)
Outputs
Pulse Output
Not available for Model 405S
Type:
Open collector output with a pulse produced on each increment of the accumulated total
Maximum Rate:
49 pulses per second
Pulse Width:
10ms
Maximum Current:
Current sinking transistor output 100mA, 30V dc maximum
4-20mA Output
Not available for Model 405S
Type:
Fully isolated output corresponding to the displayed flow rate, suitable for driving a recorder or controller. Outputs available are 4-20mA, 0-20mA, 0-10V or 2-10V, with the minimum and maximum levels programmable
Resolution:
10 bits
Accuracy:
<0.05%
Maximum Load:
500 ohms from internal power, 950 ohms if externally powered
Communications Output
Type:
RS232, RS422 or RS485 interface is available for driving printers and communicating with computers
Baud Rate:
300 to 9600
Parity:
None, odd and even
Data Bits:
7 or 8
Protocols:
A number of protocols are included to interface to printers and computers
Time/Date:
A real time clock provides time/date printing on tickets
ID Code:
For multi-point communications, a unique address can be programmed
High/Low Flow
Type:
Two Form C relays provide a high and low flow rate alarm. Alarm points are programmable during set-up
Maximum Current:
5A
Maximum Voltage:
250V ac, 30V dc
Maximum Power:
1250VA
Approvals
Electrical
ETL (US) approved to UL 508 and CSA.
Interference
CE Compliance
Optional Enclosures
Field Enclosures
IP67 (Nema 4X)
Explosion Proof Enclosures
CENELEC, FM, CSA and SAA approved enclosures available for hazardous areas
Important: Specifications are subject to change without notice.
Terminal Descriptions
| Terminals Common to all models | |
|---|---|
| No. | |
| 1 | Calibration |
| 2 | Switch Common |
| 11 | DC Power Out |
| 12 | DC Ground |
| 13 | DC Power In |
| RS232/422 Options All Models | |
|---|---|
| No. | |
| 20 | RS232 Signal Ground |
| 21 | RS232 Data In |
| 22 | RS232 Data Out |
| 23 | RS422/485 (-) Data Out |
| 24 | RS422/485 (+) Data Out |
| 25 | RS422/485 (-) Data In |
| 26 | RS422/485 (+) Data In |
| 27 | RS232 CTS |
| Isolated 4-20mA Output Option | |
|---|---|
| No. | |
| 20 | Not Used |
| 21 | 0 Volts |
| 22 | 0-10 Volts Out |
| 23 | -12 Volts |
| 24 | I (-) |
| 25 | I (+) |
| 26 | +15 Volts |
| 27 | Not Used |
| High & Low Relay Alarm Option | |
|---|---|
| No. | |
| 31 | High - Normally Open |
| 32 | High - Normally Closed |
| 33 | High - Common |
| 34 | Low - Normally Open |
| 35 | Low - Normally Closed |
| 36 | Low - Common |
Terminals 28,29 & 30 on the option card are not used.
Terminals specific to each model
| No. | 405A | 405B | 405D | 405LA | 405LR | 405Q & 405S | No. |
|---|---|---|---|---|---|---|---|
| 3 | Rate Switch | Not Used | Rate Switch | Flow Input Ch. 2 | Flow Input Ch. 2 | Flow Input Ch. 2 | 3 |
| 4 | Total Switch | Not Used | Total Switch | Not Used | PT100 (+) | Not Used | 4 |
| 5 | Reset Switch | Not Used | Reset Switch | Temp. (4-20mA) | PT100 Signal (+) | Not Used | 5 |
| 6 | Program Switch | Not Used | Program Switch | Not Used | PT100 Signal (-) | Not Used | 6 |
| 7 | Not Used | Not Used | Not Used | Flow Alarm | Flow Alarm | Flow Alarm | 7 |
| 8 | Flow Common | Flow Common | Flow Common | Flow Common | Flow Common | Flow Common | 8 |
| 9 | Flow Signal (mA) | Flow Signal | Flow Signal | Flow Input Ch. 1 | Flow Input Ch. 1 | Flow Input Ch. 1 | 9 |
| 10 | Pulse Out | Not Used | Pulse Out | Pulse Out | Pulse Out | Pulse Out | 10 |
| 14 | Flow Signals (Volts) | Not Used | Not Used | Flow Input (4-20mA) | PT100 (-) | Not Used | 14 |