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Sensyflow P

Thermal Mass Flow Meter for AirFor Motor Test Rigs and Quality Assurance

Operating Instructions

Rev. 11/2001

ABB Automation

Sensyflow P: Operating instructions

Table of Contents

1 Preface.................................................................................................3 1.1 Symbols ............................................................................................................................................ 3 1.2 Important preliminary information ..................................................................................................... 3 1.3 Sensyflow P advantages..................................................................................................................... 3

2 Device Description .............................................................................4 2.1 Front view ......................................................................................................................................... 4 2.2 Back view......................................................................................................................................... 4

Power supply ............................................................................................................................................ 5 D-Sub Output............................................................................................................................................ 5 BNC Output and Sensor connection........................................................................................................... 5

3 Commissioning...................................................................................6

4 Measuring Principle ...........................................................................7

5 Measuring Tube..................................................................................8

6 Supply/Evaluation Unit ....................................................................10 6.1 Display Unit .................................................................................................................................... 10 6.2 Options............................................................................................................................................ 11

6.2.1 Measuring Rate........................................................................................................................ 11 6.2.2 Fast Measuring Rate................................................................................................................. 12 6.2.3 Analog Outputs........................................................................................................................ 12

6.3 Temperature Measurement............................................................................................................... 13 6.4 Operation with 2 measuring tubes .................................................................................................... 14 6.5 Digital Interfaces ............................................................................................................................. 14

6.5.1 12-Bit-Parallel Interface ........................................................................................................... 15 6.5.2 Serial Interface......................................................................................................................... 15 6.5.3 Totalizer .................................................................................................................................. 22

6.6 Dimensions of the supply/evaluation unit ......................................................................................... 24

7 Measuring Set-Up.............................................................................25

8 Calibration.........................................................................................27

9 Accessories ......................................................................................28

10 Technical Data ..................................................................................29 10.1 Further mass / standard-volume flow units ....................................................................................... 30 10.2 Pressure drop of Sensyflow P measuring tubes ................................................................................. 30 10.3 Pressure drop of air filters ................................................................................................................ 30

11 Electrical Connections.....................................................................31 11.1 BNC-outputs ................................................................................................................................... 31 11.2 Probe connection 1 + 2 .................................................................................................................... 31 11.3 SLOT 1: 25-pole D-SUB connection “Serial Output” ....................................................................... 31 11.4 SLOT 2: 25-pole D-SUB connection “12-Bit Parallel Output”.......................................................... 32 11.5 SLOT 3: 25-pole D-SUB connection “Totalizer” with 15-Bit parallel interface ................................. 33 11.6 SLOT 4: 25-pole D-SUB connection “Analog Outputs” ................................................................... 34

11.6.1 Digital coding of the measuring tube ........................................................................................ 34


1 Preface 1.1 Symbols

Danger: This symbol means, that a danger of physical damage for the user can occur in case of non-observance of the operating instructions.

Warning: This symbol indicates a damage warning for the mass flow meter or other connected items.

1.2 Important preliminary information Please read these mounting and operating instructions carefully before installing and commis-sioning the system. The safe and undisturbed operation of the Sensyflow P mass flow meter requires proper transporta-tion and storage. Only qualified technicians may install and commission the measuring system. Quali-fied persons are also required for operation and maintenance. Please pay attention to - the content of these operating instructions - the appropriate security regulations for the installation and operation of electrical plants Regulations and Technical Standards mentioned in these operating instructions are valid for use within the Federal Republic of Germany. For use in other countries, please refer to the appropriate national standards. The mass flow meter was built and tested according to DIN VDE 0411 Part 1 ”Schutzmassnahmen für elektronische Messgeräte” and was shipped from the factory in a secure condition. To keep it in a secure condition and assure a safe operation, the safety rules mentioned in these operating instructions must be observed strictly. Otherwise a risk of physical damage for per-sons may occur. Also, the mass flow meter itself or connected items could be damaged. If you experience difficulties with the system or have technical questions which you are unable to re-solve with these operating instructions, then please consult our service centre or telephone our cus-tomer service office directly:

Sensyflow Hotline: Phone ++49 6023 92 3267 Fax ++49 6023 92 3210 To help us answer your queries as quickly as possible please state - the serial number - our order number

1.3 Sensyflow P advantages The demanding requirements of modern easy-to-use measuring technique in research & development and production have determined the conception of this air mass flow meter Sensyflow P. The measuring system Sensyflow P is suitable for flow measurement of air - with high accuracy - with fast installation without problems - over a wide measuring range - with high stability in continuous operation - with short response time - with easy handling - as direct mass flow measurement Sensyflow P is the reference system in the world-wide automotive industry for mass flow measure-ment of air.


Gehäuse Housing

2 Device Description

2.1 Front view

TEMP Displays the gas temperature RESET SAMPLE RATE Damping SENSOR-SELECT Selection of sensor # 1 or # 2 UNIT-SELECT Switch to the second measuring unit (e.g. Nm³/h)

2.2 Back view

Digital Display

Damping


Power supply

Operating voltage Please make sure that the correct supply voltage is connected to the system ! • ON/OFF main switch • Socket for 3-pole power-plug with internal

fuse (see instructions at the back of the appa-ratus)

D-Sub Output • 25-pole D-SUB connection

“Serial Output” (Option) • 25-pole D-SUB connection

“12-Bit-Parallel-Output” (Option)

• 25-pole D-SUB connection “Totalizer” (Option)

• 25-pole D-SUB connection

“Analog Output” (Standard)

BNC Output and Sensor connection • Analog output 0 – 10 V

via BNC-socket • Connection of measuring tube 1

(7-pole) • Connection of measuring tube 2 (Option)

(7-pole) • Analog output 0 (4) – 20 mA

via BNC-socket (Option)


3 Commissioning 1. Special attention must be paid to the correct flange connection and the flow direction, when the

transmitter (measuring tube) is installed into the measuring section. 2. Connect the transmitter (measuring tube) and the supply/evaluation unit with the transmitter cable

(7- pole). Please use only original Sensyflow cables.

3. Connect the supply/evaluation unit with the attached power cable to the supply voltage, permitted for this system.

4. Switch on the measuring system by pressing the ON/OFF main switch at the rear of the supply/

evaluation unit. Remarks: • Prior to the actual measuring mode, a self-test takes place, that shows all possible read-outs on

the “display”. After one minute the system is ready for operation and after about half an hour the full measuring accuracy will be achieved.

• The pre-adjusted measuring rate is N = 100. If a different measuring rate is desired (option),

please refer to chapter 6.2.1. • After disconnection of probe and supply/evaluation unit, e.g. after a change of probes, the “RE-

SET” button has to be pressed. • The error message “E 02” is shown on the display, if no measuring tube is connected, or a fault in

the system occurred. • If the display signals “E11”, the pushbutton “TEMP” has been pressed while having applied a

measuring tube without temperature option, or a fault in the system has occurred.


4 Measuring Principle Sensyflow P works according to the principle of the hot-film anemometer. This method of measure-ment is based on the abstraction of heat from a heated body by an enveloping gas flow. The flow-dependent cooling effect is used as the measuring effect. The set-up of a hot-film anemometer with constant temperature difference is shown in Fig. 2 schematically. The gas stream flows past two temperature-sensitive resistors Rh and RT, which are part of an electri-cal bridge circuit. Due to the chosen resistance ratio Rh << RT, Rh is heated by the current Ih and RT adopts the same temperature than the gas. The current Ih is preset by the electronic control circuit to produce a constant temperature difference between the heated resistor Rh and the gas temperature. The electrical power generated with resistor Rh exactly compensates its loss of heat to the gas flow. As this loss of heat is dependent on the number of particles which collide with the surface of resistor Rh, Ih represents the mass flow rate. It is of crucial importance that the parameters of an ideal gas, which are relevant for the method of measurement, are not pressure dependent and temperature dependent only to a small degree. The small temperature dependency is compensated by the electronics. That means, that thermal mass flow meters do not need additional pressure and temperature compensation and are able to measure a mass or standard-volume flow directly. Figure 3 shows the sensor unit with the resistors at the lower right end.

Rh : thin-film resistor- heated

RT : Thin-film resistor-gas temperature

qm : massflow

Ih : heating current

Rh

RT

qm

V

Ih

Beispiel: Gasart Luft bei 0 °C

V= 10 m3

p= 1 barρ= 1,293 kg/m3

m= 12,93 kg

V= 2,5 m3 p= 4 barρ= 5,172 kg/m3

m= 12,93 kg

ρ = mV m = ρ · V

Figure 1: Advantages of mass flow measuring

Volume flow – Mass flow Type of gas: air at 0° C

Figure 2: Hot-film anemometer block-diagram Figure 3: Sensyflow P Sensor view of detail

Platinum thin-film resistors


5 Measuring Tube The heated resistor is mounted together with the temperature sensing resistor on a support in the measuring tube (Fig. 3). By using a honeycomb/mesh arrangement in the measuring tube, the flow profile at the sensor elements is forced to be stable. The sensor signal is amplified by the electronic circuitry attached to the measuring tube to a failsafe, mass-flow dependent current signal. The measuring tube is available in the following nominal sizes: probe measuring range DN 25 0(1) - 60 kg/h DN 50 0(10) - 400 kg/h DN 80 0(20) - 720 kg/h DN 100 0(40) - 1200 kg/h DN 150 0(80) - 2400 kg/h DN 200 0(200) - 4000 kg/h

The value in brackets shows the lower limit of the measuring range for which the specified accuracy is achieved. For measuring ranges in standard volume units see chapter “Technical Data”, page 30. The sensor unit can be ordered with a separate temperature sensor (option, see chapter 6.3).

Figure 4: Cut-away model of the transmitter (measuring tube)


NW ∅D ∅D1 ∅di L L1 L2 B H 50 64 80 58 180 27,5 85 80 89 108,5 80 185 30,0 93,5

100 118 132,5 109 250 62,5 108 150 165 180 153 280 77,5 131,5 200 220 240 200 330

125

102,5

92

159


6 Supply/Evaluation Unit The supply/evaluation unit is carried-out in micro-processor technique. The transmitter signal is lin-earized and directly displayed as mass flow or standard volume flow (e.g. kg/h resp. m3

N/h). Due to the micro-processor only one supply/evaluation unit is needed for any measuring tube size with standard measuring range. The supply/evaluation unit is available as 19’’ rack or as portable tabletop unit for various supply volt-ages (see chapter “Technical data” on page 29).

Figure 5: Supply/evaluation unit as portable table-top unit

The measuring range of the respective transmitter is identified automatically when the measuring tube is connected. A measuring range identification is necessary if 2 probes are connected (see chapter 6.4) and if an analog signal has to be processed. This measuring range assignment is available as a binary code at the 25-pole D-SUB connection “Analog Outputs” (see pages 34/35).

6.1 Display Unit

Figure 6: Display of the supply/evaluation unit

• A max. value of 999 999 can be shown on the 6-digit display. • The units for the indicated measuring range value appear in the field on the right side of the digital

display. Standard unit is kg/h. The indication of other units is possible (see page 30). • The indication “SENSOR 1” is illuminated when probe 1 is chosen. • The indication “SENSOR 2” is illuminated when probe 2 is chosen (compare chapter 6.4).

(Option) • The indication “TEMP 1” is illuminated when the temperature of the gas in probe 1 is interrogated.

(Option) • The indication “TEMP 2” is illuminated when the temperature of the gas in probe 2 is interrogated

(comp. chapter 6.4) (Option) • The indication “REMOTE-CTRL” is illuminated when the apparatus is used in the totalizer mode

(comp. chapter 6.5.3).


6.2 Options

6.2.1 Measuring Rate A time-average from a discrete number of single measurements can be adjusted by the user with the selector switch on the front of the supply/evaluation unit. The duration of one single measurement is approx. 3 ms (one measurement cycle). The average value of as many single measurements as adjusted is indicated and is available at the interfaces. In standard operation mode, i.e. after switching on the apparatus resp. prior to the acceptance of an ad-justed measuring rate, the apparatus automatically forms an average value of 100 single measure-ments. Time-average with less than 100 single measurements: The digital display and the serial interface will indicate measuring values that represent an average value of 100 single measurements (not less, even when adjusted). The analog outputs and the 12-bit parallel interface will transmit values according to the adjusted measuring rate. Selection of a measuring rate: 1. Select the desired measuring rate with the selector switch at the front of the evaluation unit. 2. The selected measuring rate is accepted when the push-button “SAMPLE-RATE” on the display is

pressed. The selected measuring rate appears for a short time as an acknowledgement. The following measuring value shown at the display is already the first averaged measuring value of N single measurements as selected. Please note! After switching-on the measuring system resp. after a “RESET” the apparatus works – after having finished internal test routines – with a measuring rate of N = 100. To activate the selected measuring-rate, press the “SAMPLE-RATE” button again. Example: The average mass flow rate in a time interval of 3 sec is desired. Which measuring rate has to be selected? 3 s = 3000 ms = T Time interval desired N = 1 = 3 ms = I Duration of a single measurement Set of selector switch = N Quantity of single measurements T 3000 N = —— = ———— = 1000 I 3 The measuring rate has to be adjusted at the selector switch to N = 1000. Using the 4-digit selector switch, an average value of the mass flow, representing an average value of up to 9999 single measurements, can be formed. If “0000” is selected, the duration of a measuring cycle is only 1 ms (see chapter 6.2.2). In this “FAST MODE”, the display will not show values anymore. That means: • When adjusting a small measuring rate, the unit forms an average from only a few single meas-

urements. Thus, dynamic processes can be measured and registered. • When adjusting a high measuring rate, it forms an average from many single measurements and

thus, undesired fluctuations are suppressed (Damping).


6.2.2 Fast Measuring Rate This mode of operation is selected to measure very fast, dynamic processes. The period of a measur-ing cycle comes up to 1 ms, i.e. that each ms an actualized measuring value can be expected at the analog outputs and the 12-bit parallel interface. To select this mode of operation please proceed as follows: 1. Adjust the measuring rate “0000” with the selector switch at the front of the evaluation unit. 2. Confirm this measuring rate by pressing the push-button “SAMPLE-RATE” The display will show “……..” and the operation identification “FAST MODE” will occur. Please note! To operate the basic setting of the apparatus again, it has to be re-set (press the RESET-push-button) or switched on again. After having finished the internal test routines (while all indicators are illuminated on the display), the measuring systems measures with the standard measuring rate adjustment of N = 100 again.

6.2.3 Analog Outputs Standard analog output is 0…10 V. Additionally available as options are either

0-20 mA 4-20 mA

The analog output represents the selected measuring rate (refer to chapter 6.2.1).

Sensyflow P

Splash plate

Throttle valve

Time

Figure7: Dynamic measurement: Comparison of Sensyflow P and splash plate concerning reaction time


Further signal processing units can be connected to the analog outputs, for example: • recorder • oscilloscope • transient recorder

• process computer • controller • PLC

The measuring system Sensyflow P was especially designed for applications where a fast response time on flow changes is required. Fig. 7 shows, as an example, the fast reaction of the measuring sig-nal to the opening of a throttle valve, compared to the inert reaction of a splash plate. If several successive instruments are connected to the outputs, they will have to be connected at the voltage output in parallel and at the current output in series (Fig. 8 and 9). Current output:

Sensyflow

0 - 20 mA max. load resistance 550 Ohm 4 - 20 mA max. load resistance 550 Ohm

Voltage output: Sensyflow

0 - 10 V max. current carrying capacity 4 mA

Figure 8: Successive instruments at the current output Figure 9: Successive instruments at the voltage output

Connection:

- BNC-socket (see page 31) - D-SUB-socket (see page 34)

6.3 Temperature Measurement

Figure 10: Air temperature measurement

Technical data of the Pt 100: Response time in air at v = 1 m/s:

T50

= 3 s T

90 = 10 s

Measuring range:

-20 to +100°C

Accuracy at ambient conditions: +/- 0,4°C

Display (internal) 18 V

(internal)Bridge

Pt 100

Transmitter

Analog output 4-20 mA


The gas temperature can be determined by installing an additional measuring resistor (Pt 100) into the measuring tube (option). The temperature of the gas is indicated on the display after pressing the “TEMP” button. After pressing the button again the apparatus returns to the original mode of operation (flow measurement).

6.4 Operation with 2 measuring tubes Two probes of any nominal size can be connected to the supply/evaluation unit at the same time. Both probes (e.g. DN 25 and DN 150) are permanently operable. With the “SENSOR SELECT” button, the user decides which measuring unit is active. The appropriate measuring value will be shown on the display, and be available as a digital and/or analog signal. To select the desired measuring tube please proceed as follows: Press the pushbutton “SENSOR SELECT” until the desired probe is chosen. Your choice is indicated on the display (e.g. “Sensor 1“) and/or by the coding of the 25-pole D-SUB-connection (see pages 34/35)

6.5 Digital Interfaces The digital interfaces transmit the same mass flow value as the analog output. Analog/digital conver-sion occures without loss of accuracy. All signals leads of the digital interface are electrically isolated. Electrical isolation: The electrical isolation is achieved by an optical isolator. An optical isolator consists of a light-emitting diode and a phototransistor (Fig. 11).

Figure 11: Optical isolator


6.5.1 12-Bit-Parallel Interface The flow value is available as binary-coded, parallel 12-bit data word (electrically insulated, with DATA-READY-BIT) (Fig. 12). The digital output represents the average mass flow rate m as 12-bit-binary data word. To be able to identify the validity of the data word an additional DATA-READY-BIT is used. DATA

Ready 20 21 22 23 24 25 26 27 28 29 210 211

Figure 12: 12-bit data word with DATA-READY-BIT

The data bits are set according to the negative logic. If the DATA-READY-BIT is logic 1, the data will be valid. A complete data edge change of the DATA-READY-BITS resembles a change of the data word from the “old data” to the “new data”. The data bits may only be interrogated when the DATA-READY-BIT has been set in logic 1. The impulse diagram shown in Fig. 13 represents the change of signal of the DATA-READY-BIT and the DATA-BIT.

Figure 13: Voltage characteristics at the collector-emitter of the open-collector output

6.5.2 Serial Interface General The serial interface (V24/RS 232 C) allows the digital transmission of measuring values as well as the control of all possible operator functions of the supply/evaluation unit (bi-directional communication). Only three leads are necessary to exchange all signals between the communicating systems. Ad-dresses, data and control information must be transferred bit by bit. There can be distinguished syn-chronous and asynchronous serial interfaces. Synchronous Serial Data Transmission At certain intervals the sender adds a synchronization mark to the data flow. This mark will be identi-fied by the receiver by a special logic and so eventual shifts can be corrected until synchronization has been established between sender and receiver.


Asynchronous Serial Data Transmission The transmission of data in small units of identical length without additional clock information is called asynchronous clock-free data communication. Transmission conditions between sender and receiver must be pre-arranged like this (example): • transmission rate (baud rate) • word length • number of start – and stop-bits (format) • bit-assignment • signal voltage

This kind of signal transmission is very safe.

6.5.2.1 Pin Assignment The flow measuring value is available as a serial signal via a 25-pole-D-SUB connection at the back of the supply/evaluation unit (Fig. 14).

13

1

25

14

SLOT 1 • Pin 2 = TxD (Transmit Data)

• Pin 3 = RxD (Receive Data)

• Pin 7 = GND (Signal Ground)

Figure 14: 25-pole D-SUB connection of the serial interface

6.5.2.2 Electrical Characteristics The voltage levels of the sender and receiver data are conform to the EIA (Electronic Industries Asso-ciation) RS 232 C standard and are electrically insulated from the supply voltage of the sup-ply/evaluation unit (Fig. 15)

+ 8V

+ 3V

- 8V

- 3V0 V

Figure 15: Voltage levels of the sender and receiver data


6.5.2.3 Data Format An asynchronous ASCII data format with one START- and two STOP-bits is used for bi-directional data transmission (Fig. 16).

START BIT

0 1 2 3 4 5 6 7 STOP BIT

STOP BIT

Figure 16: Data format

The supply/evaluation unit is ready to receive data right after switching-on. The baud-rate is factory-adjusted to 9600 bit/s. Short symbols identification corresponding

Hex-code corresponding Decimal-code

EOT End of Transmission

04 04

LF Line Feed 0A 10 CR Carriage Return 0D 13 CLS Clear Screen 1A 26 IV Inverse Video 1B, 47, 34 27, 71, 52 DV Default Video 1B, 47, 30 27, 71, 48

Table 3: Translation table for applied control characters

Please note! All following listed control characters are transmitted but not indicated on a monitor which may be used. The following software description refers to the versions 7.10 and 7.11 (without totalizer function).


6.5.2.4 Instruction list The input command XBCR allows polling of the instruction list. If a monitor is connected the following text will appear: CLS Instruction list command description <XR> resets supply/evaluation unit CR, LF <XTT> sends general information CR, LF <XB> sends instrument list of interface CR, LF <XF> sends error-table CR, LF

<XS> sends flow value permanently in desired unit CR, LF <XH> stops output <XS> and releases interface CR, LF <XE> sends just one measuring value CR, LF <XA> sends totalizer value of the mass/standard volume in grams/litre

after the STOP-bit has been set (externally triggered) CR, LF <XZ> changes the measuring rate valid for display and analog output

CR,LF, example: <XZ0100CR>; <XZ0005CR> !!! It must be a 4-digit cycle number CR, LF

<XSR> interrogates the selected sample-rate. CR, LF <XU0> selects the first unit: kg/h. CR, LF <XU1> selects the second unit: e.g. m3

N/h CR, LF <XSW1> switches sensor 1 to the supply/evaluation unit. CR, LF <XSW2> switches sensor 2 to the supply/evaluation unit CR, LF <X$> sends length of the single strings CR, LF <XTR> sends the last measured value of temperature. If no transmitter is

connected the display will show E11, in case of damage of the Pt 100: E12 CR, LF

<XT1> switches temperature measurement sensor 1, the values will be sent after XTR; CR, LF

<XT2> switches temperature measurement sensor 2, the values will be sent after XTR. CR, LF, EOT


6.5.2.5 Listing of the telegrams being ordered by command Command Answer-telegram XECR MF: 044.30 kg/h sensor 1 NW25 CR, LF, EOT sends single measurement

value XSCR MF: 044.30 kg/h sensor 1 NW25 CR, LF, EOT sends continuously XHCR stops sending mode and releases sender

XZ0400CR CLS The sample rate is now: 400 CR, LF, EOT XZ0000CR CLS The supply/evaluation unit is in fast mode CR, LF

The display is not operable CR, LF

Each measuring value is sent to the analog output CR, LF

Certain switching operations are not operable CR, LF

and can only be altered at the front panel CR, LF, EOT XTTCR General information concerning the interface are transmitted (see page 20)XTRCR T = 035,4 °C CR, LF, EOT XACR CLS SU: 12309 gram sensor 1 NW50 CR, LF, EOT XSRCR CLS SR1: 0100 measuring cycles/SR2: 0001 measuring cycle CR, LF, EOT XRCR forces a software-reset (no feedback) XSW1CR CLS probe 1 is switched CR, LF, EOT XSW2CR CLS probe 2 is switched CR, LF, EOT XT1CR CLS the temperature of the gas at probe 1 is measured CR, LF, EOT XT2CR CLS temperature of the gas at probe 2 is measured CR, LF, EOT XBCR the complete command list is transmitted (see page above) XFCR complete error table is transmitted (see page 20) XU0CR CLS the unit is now kg/h CR, LF, EOT XU1CR CLS the unit is now m3

N/h at 20 °C, CR, LF, EOT X$CR string table is transmitted (see page 21)


6.5.2.6 General information The input command XTT CR allows polling of general information via interface. If a monitor is con-nected the following text will appear. CLS, IV General Information CR, LF Release X.XX CR, DV, LF Program Sensyflow P: CR, LF digital interface 15 bit output + data-ready

12 bit digital-out/opt. coupled

serial interface RS 232/V 24 command list serial inter-

face.: <XB>CR

analog interface 0-10V or 0-20mA/4-20mA digital coding of the sensor

dimension e.g.: NW25 sensor 1 CR, LF 1010 1100 binary

change of the measuring rate

for display 0100-9999 measuring cycles for analog output 0001-9999 measuring cycles fast-mode display will not be served, each measuring value

will be sent to analog output Temperature option measuring range: -20..+100 °C, 2-probe option Switching of 2 sensors

6.5.2.7 Error messages The input command XF CR allows polling of the error message table. If a monitor is connected the fol-lowing text will appear. CLS Error table "Sensyflow P" CR, LF 999999 Measuring value => Measuring range (standard

operation) E02 no probe connected E03 overrun of the summation register E04 One measuring value > upper range of the probe E11 No transmitter connected E12 damage of Pt 100 E13 ……

E14 ……

E15 ……

E16 ……

E17 ……

E18 ……

E19 ……

E20 ……


6.5.2.8 Length of the transmitted strings The input command X$CR allows polling of the string-table. If a monitor is connected the following text will appear: CLS Length of the transmitted strings Hex Code Length Decimal Code Length <XTT> 03AD 941 characters <XB> 0421 1057 characters <XF> 02C6 710 characters <XS> 0020 32 characters <XH> resets the interface <XE> 0020 32 characters <XA> 0020 32 characters <XZ> 0025 37 characters <XSR> 002A 42 characters <XTR> 0012 18 characters <XU0> 0022 34 characters <XU1> 002F 47 characters <XSW1> 001B 27 characters <XSW2> 001B 27 characters <X$> 03AD 941 characters <XT1> 0034 52 characters <XT2> 0034 52 characters Remarks 1.) <XS> is sending permanently 2.) Each command must be closed by CR CR, LF, EOT

Please note the following points during serial transmission: • The measuring rate (see chapter 6.2.1) always has to be determined by entering 4 digits, e.g. for

sample rate 50, please enter the command XZ_ _ 50 CR • In the case of permanent sending mode, no other mode can be selected via the serial interface.

The “RS 232 C” is blocked and can only be released by the command XHCR. • During operation of the measuring apparatus there is no competition between the serial interface

and the keyboard in the front panel. No priority circuit is provided. • During FAST-MODE operation all values and tables listed in the memory can be polled via the

serial interface (texts, temperatures, lists etc.) • In this period of time (execution) the FAST-MODE operation is interrupted (the analog value re-

mains constant). After completion of the execution the FAST-MODE-operation will be continued. • This mode of operation can be left with XRCR or XZCR.


6.5.3 Totalizer This mode of operation is used to determine the air mass passing through the measuring system dur-ing a defined, externally triggered measuring time. The result is displayed digitally and can be read out via a serial interface resp. a 15-bit parallel inter-face (binary-coded, electrically insulated) (see chapter 6.5.1). The measuring unit is always gram or Standard-litre. The measuring time TM is determined by the external START/STOP- signal at the “REMOTE-

CTRL”- input. The START- signal (falling edge at the “REMOTE – CTRL”- input) initiates the switch to the spe-

cial mode of operation and the start of the measurement. The STOP- signal is initiated by a rising edge at the “REMOTE – CTRL”- input (see Fig 18 and

chapter 6.5.1). During this special operation the “REMOTE-CTRL”- indication is illuminated on the left side of the 6- digit LED-readout on the display. The 6-digit LED-readout is blanked and the measuring rate setting is not operable. The analog output transmits the actual flow value continuously during this time. .

0 V

U external

Tm

5-24 V

Figure 18: Voltage at the „REMOTE-CTRL“-input

Please note! If during the special operation at least one measuring value is above the calibrated measuring range, all DATA-bits and the DATA-READY-BITS will be set after recognition of the STOP-signal. After return to the standard operation, “999999” appears on the display before the standard operation continues.

6.5.3.1 Presentation of the totalizer value The totalizer mass flow value can be presented in three different ways: a) indication on the display b) via 15-bit-parallel interface c) via serial interface (RS 232 C / V24) - a): “a” is usually combined with “b” or “c”. The time period, in which the totalizer value can be

seen, depends on 2 factors: • a fixed “read-out time”, about 5 s. • the adjusted measuring rate (compare chapter 6.2.1)

The result will be indicated in gram (g) or standard-litre (lN). - b): After sending the STOP-signal, the mass flow value m is available as a digital 15-bit-binary

signal. The DATA READY BIT is also available, both for about 15 s at the digital output (pin as-signment see chap. 11.5). The mass flow value m will be indicated in gram (g) or standard-litre (lN). After 5 s the system returns to standard operation mode automatically.

- c): The START/STOP- signal is also active at Pin 23 and 24 of the 25-pole D-SUB-connection.

After the measurement, the totalizer value is stored. It can be read out with the command XACR


6.5.3.2 Technical data - “Totalizer” All signals of the digital in- and outputs are optically isolated.

The outputs are connected as “Open Collector” (see chapter 11.5). Permitted measuring time TM: (10s ≤ TM ≤ 115 s) Error by measuring interval: 0.05% at TM = 100 s 0.15% at TM = 10 s Uncertainty of the air-mass measurement: ± 2% Necessary auxiliary supply UExternal 5-24 DC (I= 20 mA at 20 V) The maximum permitted measuring time depends on the mass flow (Fig. 19) The measuring range of the totalizer is limited by 2 parameters: 1) measuring time TM: 10 s ≤ TM ≤ 115 s 2) totalizer value m: m ≤ 32767g ((215 – 1) g).

Figure 19: Measuring range of the totalizer


6.6 Dimensions of the supply/evaluation unit

Instrument Dimension L l H h T t X ½ 19“ portable device 310 / 140 / / / / 19“ portable device 520 / 140 / / / / 19“ device 483 462 132 58 425 325 M6

All dimensions in mm

19‘‘ portable instrument

Required cutout for 19‘‘ unit 450 mm x 131 mm

½ 19’’ portable instrument

19’’ portable instrument19’’ device

Required cut-outfor 19” unit :450 mm x 131 mm Fo

r wiri

ng


7 Measuring Set-Up The construction of the measuring tube combines maximum accuracy with easy handling. To achieve the maximum accuracy special attention has to be paid to some requirements. The maximum accuracy of the system is guaranteed if the pipe was calibrated together with the probe. (accuracy: ± 1 % of reading can be achieved). A combination of honeycomb and mesh mounted in the measuring tube forms a stable flow-profile. This guarantees good accuracy also with non perfect inlet sections. The measuring tubes are calibrated in horizontal mounting position and do not show signal-dependency on the orientation. An optimum construction of the measuring section is presented in Fig. 20.

Figure 20: Preferred mounting of a measuring section with Sensyflow P

Instructions for the measuring set-up

• The flow direction of the measuring gas must correspond to the arrow on the probe. • If a suitable air filter is applied (see chapter 9) a defined gas inlet as well as high operational reli-

ability in non-stop operation even under difficult application conditions will be achieved. • Reverse flow and pulsation can be reduced or fully compensated connecting a buffer volume up-

stream or downstream the probe, depending on the kind of disturbance. • If an optimal measuring set-up is not possible because of space requirements (e.g. tests in a car),

the measuring tube can also be installed with simple connecting devices (rubber joint). Even with a set-up like this, the apparatus still shows good measuring result.

The measuring tube and all original accessories are constructed with highest priority for a user friendly and easy-handling design.

Air filter

undisturbed inlet zone undisturbed outlet zone

Sensyflow


To guarantee a gas mass-measurement with as few problems as possible the following in-

structions have to be observed: • The measuring tube should not be installed in heavily vibrating locations. In this case, we recom-

mend a coupling piece with a rubber joint in order to insulate the unit from the vibrating compo-nent. The honey-comb shall be protected against mechanical damage.

• Although the measuring system is dirt-resistant, particles could decrease the measuring accuracy. For this reason, we recommended the use of an air filter from our accessories program (please re-fer to chapter 9).

• To assure interference-free signal processing, only the original probe cables should be used.


8 Calibration The basis of each statement on possible error is the capability to carry out a calibration with distinctive higher accuracy. Our flow test benches for gases are constructed according to the model of the “Physikalisch-Techni-sche Bundesanstalt” (PTB). This allows us to conduct measurements with highest available accuracy. Specified measuring points defined by critical flow nozzles as standards (PTB-calibrated) are auto-matically adjusted and recorded. With this installation, which is also part of our delivery program, an accuracy of 0.4% of reading can be achieved (Fig. 21). This calibration facility is member of the German Calibration Service (Deutscher Kalibrierdienst DKD – No. 5701).

Figure 21: DKD calibration no. 5701

As an option, Sensyflow P measuring systems can be delivered with a DKD calibration certificate.


9 Accessories In order to simplify the installation of our measuring system for the user, we recommend to apply approved components from our exten-sive accessories program (Fig. 22). Tubes of different lengths as upstream or downstream tube sections are available which can be combined with an air filter. We recommend an undisturbed upstream tube section of 10 x D, a downstream tube section of 5 x D and the application of an air filter (this combination represents our calibration set-up). “D” = tube diameter.

Figure 22: Probes with various nominal widths and ac-cessories

Filter with flange

Inlet tube 10 x D with flanges (both-sided)

Outlet tube 5 x D with flanges (both-sided)

Inlet tube 10 x D with flange (one -sided)

Outlet tube 5 x D with flange (one-sided)

Pipe socket with flange (one-sided)

Center sealing

Components Typical measuring section

A measuring section 1 B measuring section 2

All dimensions in mm


10 Technical Data Measuring principle Thermal, Hot-Film-Anemometer Input Measured medium Air Measuring ranges (standard) Nominal size NW kg/h NW 25 0 ( 1)... 60 NW 50 0 ( 10)... 400 NW 80 0 ( 20)... 720 NW 100 0 ( 40)... 1200 NW 150 0 ( 80)... 2400 NW 200 0 (200)...4000 The value in brackets specifies the lower limit of the measuring range for which the given accuracy is achieved. Output Output signals Analog: 0...10 V, (< 4 mA) 0...20 mA, (load < 550 Ω) 4...20 mA, (load < 550 Ω) Digital parallel 12-bit-binary, electrically isolated Digital serial V24/RS 232 C, electrically isolated ASAM-GDI interface Accuracy (incl. hysteresis and non-linearity): < ± 1% of reading Repeatability < ± 0.25% of reading Influences Temperature effect < 0,03 %/K of reading Pressure effect < 0,2 %/100 kPa (/bar) of reading Response time T63 = 12 ms Recommended steadying length Inlet run 10 x pipe diameter D (use of air filter strongly recom-

mended) Outlet run 5 x pipe diameter D

Ambient conditions Ambient temperature for transducer -25...80 °C Ambient temperature for evaluation unit -25...50 °C Storage temperature -25...85 °C Degree of protection Transducer: IP 54 Process conditions Operating temperature Medium -25...80 °C Operating pressure Standard: 0...2,5 bar abs optional: up to 8 bar abs. (only NW 25) Mechanical construction Weight Transducer / Measuring tube depending on nominal size NW, see ordering data Evaluation unit 19"-plug-in version: 7,0 kg 1/2 19"-desktop housing: 7,3 kg 19"-desktop housing: 7,4 kg Material Transducer: aluminium, black anodized Tubes: aluminium, black anodized or Glass fibre, black coated Process connection Quick clamping pipe flange, aluminium with quick-clamp chains / rings Electrical connection Transducer: special connecting cable to evaluation unit Power supply Power supply/evaluation unit, voltage

230 V AC 115 V AC

Power consumption Evaluation unit 38 W Power-/ current consumption Transducer 10 W/≤ 600 mA Indication for ordering A measuring system consists of: – measuring tube / sensor – supply/evaluation unit – measuring section – sensor cable


10.1 Further mass / standard-volume flow units The possible units and upper limits of the measuring ranges for the different nominal sizes are listed in the following table. The standard unit is kg/h. Unit NW 25 NW 50 NW 80 NW 100 NW 150 NW 200 kg/h 60 400 720 1200 2400 4000 g/s 15 100 180 300 600 1000 m³N/h (0°C Tref.) 45 300 540 900 1800 3000 m³N/h (20°C Tref) 50 333,3 600 1000 2000 3333 lN/s (0°C Tref.) 12 80 144 240 480 800 lN/s (20°C TBez.) 13,5 90 162 270 540 900 lN /min (0°C TBez.) 750 5000 9000 15000 30000 Two of the units listed above can be selected as an option by the switch “UNIT-SELECT” at the Sensyflow supply/evaluation unit (comp. page 4).

10.2 Pressure drop of Sensyflow P measuring tubes

10.3 Pressure drop of air filters

Pressure drop [ mbar]

Mass flow

Pres

sure

dro

p [ m

bar ]

Mass flow [ kg/h ]


11 Electrical Connections 11.1 BNC-outputs

Current output: 0(4) - 20 mA Voltage output: 0 - 10 V

11.2 Probe connection 1 + 2

1 = temperature signal 2 = flow signal 3 = supply voltage (+ 18 V) 4 = probe coding 20

5 = probe coding 21 6 = probe coding 22 7 = probe coding 23

11.3 SLOT 1: 25-pole D-SUB connection “Serial Output”

Pin Assignment Pin Assignment 1 - 14 - 2 TxD Transmit data 15 - 3 RxD Receive data 16 - 4 - 17 - 5 - 18 - 6 - 19 - 7 GND 20 - 8 - 21 - 9 - 22 - 10 - 23 - 11 - 24 - 12 - 25 -

13

1

25

14

13 -


11.4 SLOT 2: 25-pole D-SUB connection “12-Bit Parallel Output”

Pin Assignment Pin Assignment 1 20 LSB* 14 21 2 22 15 23 3 24 16 25 4 26 17 27 5 28 18 29 6 210 19 211 MSB* 7 - 20 - 8 - 21 DATA-READY-BIT 9 - 22 - 10 - 23 - 11 - 24 - 12 - 25 GNDexternal

13

1

25

14

13 - * LSB = least significant bit * MSB = most significant bit

Figure 23:Terminal connection of Open-Collector outputs

User Sensyflow

Uexternal

GNDexternal RL min.= 2 KOhm Uexternal = 5 – 24 V DC


11.5 SLOT 3: 25-pole D-SUB connection “Totalizer” with 15-Bit parallel interface

Pin Assignment Pin Assignment 1 20 LSB* 14 213 2 21 15 214 MSB* 3 22 16 DATA-READY-BIT 4 23 17 - 5 24 18 - 6 25 19 - 7 26 20 - 8 27 21 - 9 28 22 - 10 29 23 REMOTE-CTRL START/STOP 11 210 24 Uexternal 12 211 25 GNDexternal

13

1

25

14

13 212 * LSB = least significant bit

* MSB = most significant bit

Figure 24: Terminal connection of in-/outputs

User User Sensyflow

Uexternal


11.6 SLOT 4: 25-pole D-SUB connection “Analog Outputs” (compare chapter 2.2)

Pin Assignment Pin Assignment 1 GND 14 I OUT GND 2 I OUT + 15 U OUT GND 3 U OUT + 16 GND 4 Measuring tube coding 17 Measuring tube coding 5 Nominal width coding 18 Nominal width coding 6 Nominal width coding 19 Nominal width coding 7 Free coding 20 Free coding 8 Free coding 21 Free coding 9 - 22 - 10 - 23 - 11 temp.1 + 24 temp. 1 12 temp. 2 + 25 temp. 2

13

1

25

14

13 GNDexternal

11.6.1 Digital coding of the measuring tube

The outputs are connected as “open-collectors”. Technical data: Collector-emitter-voltage 5 - 24 V DC load resistance RL min.: 2 K Ω log. level 0 = Uexternal log. level 1: = e.g. approx. 0,8 V (at + 15 V Uexternal; negative logic)

Figure 25: Terminal connection of probe coding

Sensyflow User

Uexternal

GNDexternal RL min.= 2 KOhm Uexternal = 5 – 24 V DC


Coding of remote input Pin 5 Pin 18 Pin 6 Pin 19 Hex 0 0 0 0 00 No measuring tube 1 1 0 0 30 NW 25 1 0 1 0 50 NW 50 1 1 1 0 70 NW 80 1 0 0 1 90 NW 100 1 1 0 1 BO NW 150 1 0 1 1 D0 NW 200 1 1 1 1 F0 Special Pin 4 Pin 17 1 1 Measuring tube 1 1 0 Measuring tube 2 0 1 Gas temperature, measuring tube 1 0 0 Gas temperature, measuring tube 2

ABB ABB Automation Products Sensycon Alzenau Subject to tec hnical changes Borsigstrasse 2 D-63755 Alzenau Tel. [+49] (0) 6023 – 92 – (0) - 3313 Tel. [+49] (0) 6023 – 92 – 3210 E-mail: sensy f low.deapr@ de. abb.com http://www.abb.com

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