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Series PC Manual V 1.0 - Rev. 3

– 03/01/01

DS Europe

6

2. WORKING PRINCIPLE

An electrical pulse is injected into the waveguide contained in the probe. This pulse
generates a corresponding magnetic pulse, which then links onto the magnetic field of the
magnets contained in the cursor and generates a magnetostrictive mechanical torque
pulse.
This

mechanical pulse

is generated along the wave guide at the velocity of sound found in

metals (about 2800 m/sec) until reaching the

sensor positioned in the head

inside the

electronics. The cursor position is caculated by measuring the time lapse between the
electrical pulse and the return mechanical pulse

2.1. NOT MEASURING DEAD LENGTH

The dead length refers to the stretch at the very far end of the measuring probe where
there is either no measurement or the measurement does not satisfy the technical
specifications of the transducer.
Series PC certificates indicate dead length values.
Probe end (A) dead length (see certificate) is generally used for mechanical anchorage of
the probe itself.

Should you require an improvement on standard linearity, you are advised to consider an
adjunctive “dead length”, of about 20 – 25 mm, positioned near the measuring head.

3. MANUFACTURING MATERIALS

3.1.

TRANSDUCER MANUFACTURING MATERIALS

The working principle requires that the manufacturing materials of the probe (cylindrical
rod), the hexagonal part and relative fastening nuts of the head and the floats be made of
non-magnetic materials.(=NM=diamagnetic).
For models bearing the suffix (-S), the probe and the union are made of AISI 316 L
stainless steel. The measuring head casing is made of die-cast aluminium alloy.
For models bearing the suffix (-A), we have aluminium alloy instead of steel.

3.2.

MANUFACTURING MATERIALS FOR PARTS NEAR TO THE

TRANSDUCER.

In order to have transducer to work correctly, the magnetic field of the cursor must close
across the magnetostrictive guide inside the transducer, even in the end areas of the A
probe and near the head.
Permanent external magnetic fields generated by other magnets or residual magnetic
fields, generated from the cursor coming into occasional contact or proximity of
magnetizable materials (paramagnetic materials), can effect the measurement.

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Содержание PC Series

Страница 1: ...TRICTIVE TRANSDUCERS SERIES PC M O D E L S P C S P C P P C R P C M DS EUROPE DS EUROPE DS EUROPE DS EUROPE S r l Via F Russoli 6 20143 MILANO ITALY Tel 0039 02 8910142 Fax 0039 02 89124848 8910145 E mail dseurope dseurope com Internet www dseurope com ...

Страница 2: ...v 3 The information in this manual can be subjected to modifications without prior notice DS Europe refuses any responsibility for possible errors contained within or possible direct or indirect accidental damages deriving from supplier from the operation or the use of this material Any reproduction modifications or translation of this manual or parts of it are strictly forbidden unless prior writ...

Страница 3: ... USER 10 6 FLOATS 11 6 1 INSTALLATION ADVICES 11 6 2 BALLAST 11 7 TRANSDUCER INSTALLATION 11 7 1 MOD PCS S STANDARD 11 7 2 MOD PCP P FLANGED WELL 12 7 3 MOD PCR WITH SLIDE 12 8 PRESSURE ACTION ON THE MEASURING PROBE 12 9 ELECTRICAL SPECIFICATIONS 12 9 1 POWER SUPPLY 12 9 2 ABSORBED CURRENT 13 9 3 SAMPLING FREQUENCY 13 9 4 RESOLUTION 14 9 5 NUMBER OF CURSORS 14 9 6 ANALOG OUTPUTS 15 9 7 RS 485 DIGI...

Страница 4: ...F THE TRANSDUCER WITHOUT HAVING TO ALTER THE STABILITY AND RESOLUTION OF THE TRANSDUCER 30 12 3 REMOTE CALIBRATION 30 14 SERIAL COMMUNICATIONS PROTOCOL 31 14 1 PROTOCOL FORMAT 31 14 2 COMMAND MESSAGE STRUCTURE 31 14 3 ACCEPTED COMMANDS 32 14 3 1 COMMAND A 32 14 3 2 COMMAND D 32 14 3 3 COMMAND L 33 14 3 4 COMMAND R 33 14 3 5 COMMAND V 33 14 3 6 COMMAND T 34 14 3 7 COMMAND X 34 14 4 TRANSDUCER REPLI...

Страница 5: ...t under these conditions DS Europe is forced to refuse any responsibility regarding use and thus limits itself to listing some fundamental and elementary precautions to ensure correct use In situations where there is a potential risk of damage or injury to people of things or machine stops and measuring systems it is the precise obligation of the User to make sure that there is adequate insurance ...

Страница 6: ...chorage of the probe itself Should you require an improvement on standard linearity you are advised to consider an adjunctive dead length of about 20 25 mm positioned near the measuring head 3 MANUFACTURING MATERIALS 3 1 TRANSDUCER MANUFACTURING MATERIALS The working principle requires that the manufacturing materials of the probe cylindrical rod the hexagonal part and relative fastening nuts of t...

Страница 7: ...wn in Figure 1 The one given in Fig 2 where the surrounding parts are made of magnetic material M soft metal usually steel should be considered very carefully and possibly avoided if we want to respect all the aforementioned conditions section 3 2 The recommended distances limit are indicated in Fig 2 mm A max 1 8 of the diameter outside of the cursor ...

Страница 8: ...der to work it is essential that their magnetic field is sufficiently high and it is entirely coupled along the waveguide 4 2 POLARITY OF MAGNETIC FIELD Magnetic field polarity is established by the Manufacturer of the Transducers No other polarity values are permitted as they might jeopardise performance For this reason be sure to follow indications in Figures 3 4 5 4 3 HOW TO RECOGNISE POLARITY ...

Страница 9: ... 2 can be filled with a non magnetic material e g aluminium 5 2 WITH AXIAL MAGNETIC FIELD Ring toroids Fig 3 They are from ARA 5F models to ARA 10E models Toroid Cursors with opposing poles on the two base planes Important in order to work correctly it is necessary that the polarity towards the measuring heads corresponds to the one indicated in Figure 3 The material ferrite F or rare earth E is h...

Страница 10: ...ile the RS485 will give a 9999999 output For performance optimisation the Customer must supply DS Europe with all the installation conditions 5 4 MAGNETS CHOSEN BY THE USER It must have a high magnetic field invariable throughout time and with a high maximum working temperature The lobe of the magnetic flow must be wide enough to interest the magnetostrictive waveguide Polarity must be as indicate...

Страница 11: ...not good axiality of the probe do not have a great effect on measuring NOTE 2 The PCS and PCP models are supplied in two versions in one version the parts which come into contact with liquid are made of stainless steel and welded to one another suffix S and in the other version these parts are made of aluminium and glued to one another suffix A In the aluminium version A great attention must be ta...

Страница 12: ... MEASURING PROBE The outside pressure has a radial direction on the external wall of the probe itself and axial on the tip of the probe A fig 3 Radial action tends to reduce press the circular walls of the probe but has no significant effect on the measurement The axial action of the pressure on the tip of the measuring probe A tends to reduce its length This is also generally negligible 9 ELECTRI...

Страница 13: ...00 mm 250 Hz Table 1 maximum sampling frequency with respect to length Whenever a remote computer should request by means of RS 485 connection 57 600 baud the Cursor 0 position measurement will have Request from remote computer 0 R 0 CR for a total of 5 characters transmitted Transducer reply 0 R 0 1 2 0 5 0 0 CR for a total of 10 characters transmitted A program that continually questions the tra...

Страница 14: ...rsor x and the full scale point calibrated with TxF control expressed in the measuring unit inside the transducer for this value is the number of distinct points that the transducer can resolve between two positions If the transducer was to have a measuring field equivalent to 1000 mm and voltage output of 0 10V we would have Example 1 Suppose that we calibrate with reference to the PCS hexagonal ...

Страница 15: ...ocity OPTION measures For various possible configurations see Table 3 For analog outputs a voltage of 0 00Vcc is not obtainable as the transducer is supplied with only positive voltage The minimum voltage is about 50 mV typical These values can be reduced by using the mass dedicated to it as a reference for the analog signal yellow wire or 5 pin refer to chapter 10 IMPORTANT NOTE the outputs can o...

Страница 16: ...version in transparent way with full RS485 protocol management On today s market we have passive and intelligent converters The passive ones however are ill advised as they only provide relative signal level adaptation to two protocols whereas the intelligent converters recommended type also provide the data flow direction recognition and self adapting serial transmission velocity For any further ...

Страница 17: ... according to following instructions In the case of interconnections longer than 5 meters use conductors with diameters greater than 1 mm In any case It is to use only 100 shielded cables In the following text the indications refer to the cable leads option C output with cable in brackets we have indications about connector pins option P connector output Example WHITE PIN3 means WHITE output with ...

Страница 18: ...PLY 3 ANALOG OUTPUT 1 A D1 4 ANALOG OUTPUT 2 A D2 5 ANALOG OUTPUT 6 DATA RS 485 7 DATA RS 485 Table 2 Connection to transducer connector 10 3 POWER SUPPLY CONNECTION Figure 6 shows how to connect the transducer to a stabilized and filtered power supply which is to supply a voltage of 24 VDC and a current of at least 100 mA better to choose power supply with 0 5 A min current considering the operat...

Страница 19: ...wn because the protection diode will stop It Series PC has an overvoltages protection system For voltages above 30 Vcc this diode comes into action and short circuits the power supply thus protecting the transducer from voltage pulses from drives motors remote controls etc The maximum duration of overvoltage must never exceed 1 msec because after this period the component will be damaged in an irr...

Страница 20: ...ion allows us to separate feedback signal from the input and improve signal stability 10 5 CONNECTION OF TWO VOLTAGE ANALOG OUTPUTS 0 10V Connect the YELLOW wire PIN5 to the negative of the multi meteres or data acquisition card Connect the WHITE wire PIN3 to the positive of the first multi meter and the GREEN wire PIN4 to the positive of the second multi meter figure 8 Electrical connection for t...

Страница 21: ...o current outputs The maximum load resistance RLoad for the two current outputs is 600 Ohm 10 6 1 CURRENT CONNECTION 4 20 mA WITH VOLTAGE READING 1 5 V Figure 9 shows the electrical connection of the current output 4 20 mA but read as a voltage This measurement is obtained by connecting a 250 ohm resistor to the output of the transducer The resistor covered by the 4 20 mA consents us to visualise ...

Страница 22: ...ouble shielding it is preferable to connect the shields to ground so that the internal shield is connected to ground at on end towards the transducer for example and the external shield is connected to ground at the opposite end towards the computer for example This procedure must also be done when the interconnection cable is passing through metal conducts in order to obtain more efficient shield...

Страница 23: ...at is indicated in this manual The transducer is fitted with input filters for power supply for the analog output signals and for digital signals The use of such filters may be necessary depending on environmental conditions in which the unit is installed In order for these filters to operate correctly the transducer needs to be connected to a ground free from interference produced by other equipm...

Страница 24: ...g description 11 2 YELLOW LED Yellow LED shows information about the inner transducer way of working and also about errors listed in the table during the transducer working and when calibrating with push buttons X and Y blinking codes X shows the kind of error and Y which cursor generates the error Blinking code X Code Y Code Normal transducer condition 1 Number of set cursor 1 or 2 No STOP signal...

Страница 25: ...ve interference put the interconnection cable inside a steel tube paramagnetic with external insulation and connect it to ground near the transducer from the opposite side of the cable shield Apply all the ground and safety regulation Where there are long stretches of interconnecting cables solder cable joints inside the metal junction boxes The shielding must not be locally grounded in the casing...

Страница 26: ...Series PC Manual V 1 0 Rev 3 03 01 01 DS Europe 26 ...

Страница 27: ...if transducer has D A 1 On the field it is only possible to calibrate the zero and full scale positions The result of the operation will be read by a tester positioned at output of D A converter 1 between White and Yellow wires Calibrating operation always use D A converter 1 For convenience reasons the cursor or float nearest to the electronics red casing with electrical output is referred to as ...

Страница 28: ...tion error and then restart calibration procedure by pressing push button A 13 2 2 1 cursor 8 Cursor 1 is beginning to be calibrated when push button B is pressed for approx 2 sec till YELLOW LED is off 9 D A converter 1 output is fluctuating from 5 to 7 5V square wave with 0 25Hz frequency 10 Cursor 1 is to be placed on zero point when push button B is pressed the YELLOW LED will blink once for 1...

Страница 29: ...l blink for 1 sec confirming the FULL SCALE point memorization IS YELLOW LED ALSWAYS ON Analog output of A D1 is fluctuating between 5 V and 7 5 V Move cursor onto ZERO position Press push button B and Yellow LED will blink once for 1 sec confirming the ZERO point memorization Analog output of A D1 is fluctuating between 7 5 V and 10V Move cursor to FULL SCALE point Press push button B and Yellow ...

Страница 30: ...ilt in EEPROM memory With this kind of memory the data storage is mantained even when there is no transducer power supply nor a built in battery One of the features of EEPROM memories that must always be considered while using the transducer is that despite the fact the maximum number of storage cycles on these memories is very high it is finite a maximum of 10 000 typical storage cycles according...

Страница 31: ...h an ASCII message initial character 0x40 This character always takes first place in the message construction Afterwards we need to insert the identification ID of the transducer to which the command is being addressed The ID must always be expressed as a number between 0 and 9 or a letter between A and Z capital or simply by a question mark when you wish to send a message to a transducer for whic...

Страница 32: ...to connect up to it using the Example A 1 cr 14 3 2 COMMAND D The command D allows to program the configuration byte of the D A converters thus setting their way to operate The command can be summarised by the format Dbbbbbbbb where D is the real true command and bbbbbbbb are the 8 bits which make up the byte each b can only be a value 0 or the value 1 The bits are numbered from right to left The ...

Страница 33: ...ctronics connector or cable output while the cursor 1 refers to the furthest one see figure 13 IMPORTANT NOTE after entering the new parameters in order for them to have effect it is necessary to switch the transducer off and then switch it on again In this way the internal coefficients can be recalculated Example 1 0 L0L 000000 cr The lower reference ZERO of cursor 0 is set at a value of 0 mm Exa...

Страница 34: ...f and then switch it on again In this way the internal coefficients can be recalculated To ensure correct transducer operation it is necessary to calibrate the transducer so that the correlation summarised here can be observed ZERO FULL SCALE Set reference Memorise measurement Set reference Memorise measurement Cursor 0 0L0Lxxxxxx 0T0Z 0L0Hxxxxxx 0T0F Cursor 1 0L1Lxxxxxx 0T1Z 0L1Hxxxxxx 0T1F Note ...

Страница 35: ...Z 7 Maximum Calibration 1 Internal count value maximum 1 0T1F 8 A D Configuration A D converters bit configuration 0Dbbbbbbbb 9 Serial address Transducer serial ID 0Ax Table 4 table of parameters in memory Example 0 X 0 cr In the example the contents of the 0 parameter are read cursor 0 ZERO refernence Note xxxxxx yyyyyy zzzzzz wwwwww are 6 figure subjects of commands used to program the transduce...

Страница 36: ...rs command L The measurement is given without decimal points If for example the configuration parameters have been defined in tenths of a millimeter the value of the position measurement will be given in tenths of a millimeter The program which questions the transducer to know the position of the cursors will have to get It accordingly to the configuration setup yR9999999 cr This is the reply to t...

Страница 37: ... 5 EN 61000 4 2 EN 61000 4 8 ENV 50204 Manufacturer DS Europe srl Address via F Russoli 6 Milan Italy Type of equipment Position and magnetostrictive level transducers Models PC series Mod PCS Mod PCP Mod PCR Mod PCM With analog and digital outputs Year of marking 1999 Th equipment has been tested with the typical installation configuration as prescribed by the product instruction manual DS Europe...

Страница 38: ...defects Any units which prove to be defective despite the above mentioned controls shall be repaired or replaced free of charge by DS Europe on the conditions that the units have been subject to normal or correct use and in any accordingly with the use described in the herein manual and that such units shall be delivered to the DS Europe office by the Customer who will have to forfeit the costs fo...

Страница 39: ...Series PC Manual V 1 0 Rev 2 DS Europe 39 NOTE ...

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