EFTA01216716.pdf

Operating Instructions Edition 12/2003 Transmitter for pressure, differential pressure and flow, filling level, SIEMENS absolute pressure from differential pressure 7MF4*34-... I EFTA01216716 EFTA01216717 SIEMENS SITRANS P, DS III PA series 7MF4*34-... Edition 12/2003 Operating Instructions Transmitters for Pressure, Differential Pressure and Flow, Filling Level Absolute pressure from differential pressure series and absolute pressure from pressure series, DS III series with PROFIBUS-PA Edition of Firmware identification System integration Installation path operating License plate PDM manual 02 FW: 300.01.03 PDM V.5.02 + SP1: SITRANS P DSIII FW: 300.01.04 Dev. R.1/2 FW: 300.01.05 FW: 300.01.06 03 FW: 300.01.07 PDM V.5.02 + SP1; SITRANS P DSIII Dev. R.1/2 04 FW: 300.01.07 PDM V.5.02 + SP1; SITRANS P DSIII Dev. R.1/2 Table 1 History of this instruction manual SITRANS P. DS III PA series A5E00053276-04 1 EFTA01216718  SITRANS P. DS III PA series 2 ASE00053276-04 EFTA01216719 Table of contents Classification of Safety—Related Notices 7 General Notes 8 Technical description 11 1.1 Application range 11 1.2 Product features 11 1.3 Measuring type 12 1.3.1 Pressure 12 1.3.2 Differential pressure and flow 12 1.3.3 Filling level 12 1.3.4 Absolute pressure 13 1.4 Design and functional principle 13 1.4.1 Design 13 1.4.2 Mode of operation 16 1.4.2.1 Mode of operation of the electronics 16 1.4.2.2 Pressure 18 1.4.2.3 Differential pressure and flow 18 1.4.2.4 Filling level 19 1.4.2.5 Absolute pressure from the differential pressure series 19 1.4.2.6 Absolute pressure from the pressure series 20 2 Communication structure for PROFIBUS PA 21 2.1 Block model for recording and processing measured values 21 2.1.1 Pressure measuring block 22 2.1.2 Electronics temperature measuring block 22 2.1.3 Analog input function block 22 2.1.4 Counter function block 22 2.1.5 Local operation and display 22 2.1.6 Connection between the blocks using parameters 23 2.1.7 Parameters for measured value display 23 2.2 Description of individual blocks 24 2.2.1 Pressure measuring block (Transducer Block 1) 24 SITRANS P. Series DS III PA ASE00053276-04 3 EFTA01216720 2.2.1.1 Type of linearization function group 25 2.2.1.2 Units for the pressure measuring block 28 2.2.2 Electronics temperature measuring block 28 2.2.3 Analog input function block 29 2.2.4 Counter function block 30 3 System integration 33 3.1 Cyclic data transmission 33 3.1.1 Setting the PROFIBUS address 33 3.1.2 Configuration 33 3.1.2.1 Configuring the user data 34 3.1.2.2 Transmission of user data via PROFIBUS 35 3.1.2.3 Status 36 3.1.2.4 Diagnosis 39 3.2 Acyclic Data Transmission 41 3.3 SIMATIC PDM 41 4 Local operation and display 43 4.1 General operating instructions 43 4.1.1 Digital display 43 4.1.2 Measured value display 44 4.1.3 Unit display 44 4.1.4 Error signaling 44 4.1.5 Mode display 45 4.2 Operation with the keyboard 45 4.2.1 Measured value display 47 4.2.2 Error display 47 4.2.3 Mode 4: Electric damping 48 4.2.4 Mode 7: Zero point adjustment (position error correction) 48 4.2.5 Mode 10: Key lock 49 4.2.6 Mode 13: Source of measured value display 49 4.2.7 Mode 14: Physical unit 51 4.2.8 Mode 15: PROFIBUS address 54 4.2.9 Mode 16: Device operating mode 54 4.2.10 Mode 17: Position of the decimal point 55 4.2.11 Mode 18: Zero point adjustment display 55 4.2.12 Mode 19: LO adjustment 56 4.2.13 Mode 20: HI adjustment 57 5 Functions/Operation via PROFIBUS-PA 59 5.1 Measuring operation 59 5.2 Settings 59 5.2.1 Pressure measurement 60 5.2.2 Filling level (level, volume and mass) measurement 60 5.2.2.1 Level measurement 60 5.2.2.2 Volume measurement 61 5.2.2.3 Mass measurement 62 5.2.3 Flow measurement 63 5.2.3.1 Application point for the root function, creep quantity suppression 64 SITRANS P. Series DS III PA 4 A5E00053276-04 EFTA01216721 5.2.3.2 Flow measurement correction 65 5.2.4 Adjustment to the desired process variable 65 5.2.5 Electric damping 67 5.2.6 Warning and alarm limits 67 5.2.7 Fault Behavior 69 5.2.7.1 Output 69 5.2.7.2 Counter output 69 5.2.8 Simulation 70 5.2.8.1 Output simulation 70 5.2.8.2 Input simulation 70 5.2.8.3 Pressure sensor simulation 71 5.2.8.4 Simulation of the sensor and electronics temperature 72 5.2.9 Calibration interval and service interval 72 5.2.9.1 Warning 73 5.2.9.2 Alarm 73 5.2.10 Slave pointers 73 5.2.11 Operating hours counter 74 5.2.12 Sensor adjustment 75 5.2.13 Positional error adjustment 76 5.2.14 Resetting 76 5.2.14.1 Resetting to delivery status 76 5.2.14.2 Restart (warm start) 76 5.2.14.3 Resetting the PROFIBUS address to 126 77 5.2.15 Operator input inhibits 77 6 Modular design 79 7 Installation 81 7.1 Installation (except filling level) 82 7.1.1 Mounting without mounting bracket 83 7.1.2 Mounting with mounting bracket 83 7.2 Mounting "filling lever 85 7.2.1 Installation 85 7.2.2 Connecting the low pressure line 85 7.3 Rotating the measuring cell in relation to the housing 87 7.4 Electrical Connection 89 7.4.1 Connection to screw terminals 90 7.4.2 Connection with plug M12 91 7.5 Turn digital display 93 8 Commissioning 95 8.1 Pressure, absolute pressure from the differential pressure series and absolute pressure from the pressure series 96 8.1.1 Measuring gases 97 8.1.2 Measuring vapor and liquid 98 8.2 Differential pressure and flow 99 8.2.1 Measuring gases 99 8.2.2 Measuring liquids 100 8.2.3 Measuring vapor 102 SITRANS P. Series DS III PA ASE00053276-04 5 EFTA01216722 9 Technical data 103 9.1 Nominal measuring ranges and overload limits 108 9.1.1 Pressure 108 9.1.2 Differential pressure and flow 108 9.1.3 Absolute pressure from the pressure series 109 9.1.4 Absolute pressure from the differential pressure series 109 9.1.5 Filling level 110 9.2 Dimensions 110 10 Care and maintenance 115 11 PROFIBUS 117 11.1 Transmission method 117 11.2 Topology 117 11.3 Properties of the PROFIBUS PA 119 11.3.1 Profile 119 11.3.2 Interfacing 120 12 Ordering Data 123 12.1 Ordering data for basic device 124 12.2 Ordering data for spare parts 131 12.3 Ordering data for accessories 135 13 Certificates 137 14 Index 139 15 139 16 Appendix 141 16.1 Literature and catalogs 141 16.2 Summary of error messages and status codes 142 16.3 Certificates 146 SITRANS P. Series DS III PA 6 A5E00053276-04 EFTA01216723 Classification of safety—related notices This manual contains notices which you should observe to ensure your own personal safety, as well as to protect the product and connected equipment. These notices are highlighted in the manual by a warning triangle and are marked as follows according to the level of danger: DANGER indicates an immenently hazardous situation which, if not avoided, will result in death or serious inury. WARNING iindicates a potentially hazardous situation which, if not avoided, could result in death or serious injury. CAUTION used with the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage. NOTICE indicates a potential situation which, if not avoided, may result in an undesirable result or state. NOTE rTe ihighlights important information on the product, using the product, or part of the documentation that is of particular importance and that will be of benefit to the user. Copyright Siemens AG 2001 All rights reserved Disclaimer of Liability The reproduction. transmission or use of this document We have checked the contents of this manual for agreement or its contents is not permitted without express written with the hardware and software described. Since deviations authority. Offenders will be liable for damages. All rights, cannot be precluded entirely. we cannot guarantee full including rights created by patent grant or registration of agreement. However. the data in this manual are reviewed a utility model or design, are reserved. regularly and any necessary corrections included in subsequent editions. Suggestions for improvement are Siemens AG welcomed. Bereich Automatisiwungs- and Antriebstechnik Geschaftsgebiet Process Instrumentation Siemens AG 2001 0-76161 Karlsruhe Technical data subject to change. SITFtANS P. Series OS III PA A5E00053276-03 7 EFTA01216724 General notes This device has left the factory in a perfect condition as regards safety. The notes and warnings in these Operating Instructions must be observed by the user if this state is to be maintained and hazard-free operation of the device assured. NOTE Dear customer, You have purchased a modular device in which you can exchange the electronics. In the event of an exchange, please observe the instructions enclosed with the component to be exchanged. For reasons of clarity the manual does not contain detailed information about all types of products and cannot take into account every conceivable case of installation, operation or maintenance. If you require further information or should problems occur which are not sufficiently explained in the manual, you can consult your local Siemens branch to obtain the necessary information. May we also draw your attention to the fact that the contents of the manual are not part of a previous or existing agreement, approval or legal relationship or an amendment thereof. All obligations of the Siemens AG result from the contract of purchase which also contains the full and solely valid warranty agreement. These contractual warranty conditions are neither extended nor restricted by the contents of the manual. The contents reflect the technical state at the time of going to print. Subject to technical modifications in the course of further development. WARNING Explosion-proof devices may only be opened when the power is off. Intrinsically safe devices lose their license as soon as they are operated on circuits which do not meet the test requirements valid in your country. The device may be operated with high pressure and corrosive and dangerous media. Therefore serious injuries and/or considerable material damage cannot be ruled out in the event of improper handling of the device. The perfect and safe operation of this equipment is conditional upon proper trans- port, proper storage, installation and assembly as well as on careful operation and commissioning. The equipment may only be used for the purposes specified in the instruction manual. Excluded Liability The user is responsible for all changes made on the device, provided that these are not explicitly mentioned in the instruction manual. SITRANS P. Series DS III PA 8 A5E00053276-03 EFTA01216725 Qualified Personnel are persons familiar with the installation, assembly, commisioning and operation of the product and who have the appropriate qualifications for their activities such as: • training or instruction or authorization to operate and maintain devices/systems according to the standard of safety technology for elecrical circuits, high pressures and corrosive as well as hazardous media. • for devices with explosion protection: training or instruction or authorization to be allowed to work on electrical circuits for potentially explosive systems. • training or instruction according to the standards of safety engineering in the care and use of suitable safety equipment. CAUTION Modules which are sensitive to electrostatic charge may be destroyed by voltages which are far below the human level of perception. These voltages occur already when you touch a component or electrical connections of a module without first discharging yourself electrostatically. The damage incurred by a module as a result of an overvoltage is not usually immediately perceptible but only becomes noticeable after a long time in operation. Therefore, a suitable equipotential bonding must be guaranteed when repairing the device. Trademarks SIMATIC®, SIPART®, SIREC®, SITRANS® are registered trademarks of Siemens AG. Third parties using for their own purposes any other names in this document which refer to trademarks might infringe upon the rights of the trademark owners. SITRANS P. Series OS III PA A5E00053276-03 9 EFTA01216726  SITRANS P. Series DS III PA 10 A5E00053276-03 EFTA01216727 Technical description I NOTE IIr The transmitter must warm up for about 5 minutes after switching on the power in order to obtain stable measured values. 1.1 Application range The SITRANS P, Series DS III PA transmitter measures the pressure of non- corrosive and corrosive as well as critical gases, vapors and liquids. You can use it in the following applications • Pressure • Differential pressure • Level • Volume • Volume flow • Mass flow rate The transmitters are available with different designs of pressure-transmitting seals for special applications, e.g. measuring highly viscous substances. The device can be operated as a stand-alone unit or using its PROFIBUS interface. 1.2 Product features • Transmitter with bus connection according to IEC 61158-2 and EN 50170 • Transmitter designs with intrinsic safety against explosion can be installed in SITRANS P. Series OS III PA A5E00053276-04 11 EFTA01216728 Technical description areas where there is an explosion hazard. • The certificate of conformity meets the European rules (CENELEC). • Data transmission and auxiliary power (9 to 32 V) via bus connection together • Bus connection independent of polarity and fixed bus current limiting in the event of an error • Contact separation (test voltage 500 V AC) • Intrinsically-safe and flameproof version for use in explosion protected area (Ex- area) • Can communicate through PROFIBUS-PA (profile version 3.0, Class B); • The transmitter can be parameterized locally using three buttons or externally via SIMATIC PDM. 1.3 Measuring type 1.3.1 Pressure This version of the device measures the pressure of non-corrosive and corrosive as well as critical gases, vapors and liquids. Can be operated with measuring cells from 1 to 400 bar. 1.3.2 Differential pressure and flow This version of the device is used to measure • the differential pressure, e.g. the active pressure, • of a small positive or negative excess pressure, • of the flow q 1670 (together with a flow control valve) non-corrosive and corrosive and ciritical gases, vapors and liquids. Can be operated with measuring cells from 20 mbar to 30 bar 1.3.3 Filling level This version of the device with mounting flange measures the filling level of non- corrosive and corrosive as well as critical liquids in open and closed containers. Can be operated with measuring cells from 250 mbar to 5 bar The nominal width of the mounting flange is DN 80 or DN 100 or 3 or 4 inch. In the filling level measurement on an open container the low pressure connection of the measuring cell remains open (measurement "compared to atmospheric"), in the measurement on a closed container this connection is usually connected to the vessel to compensate the static pressure. SITRANS P. Series DS III PA 12 ASE00053276-04 EFTA01216729  Technical description The wetted parts are made of different materials (see chapter 9, pg. 103) according to the required corrosion resistance. 1.3.4 Absolute pressure This version of the device measures the absolute pressure of non-corrosive and corrosive as well as critical gases, vapors and liquids. There are two series: one "differential pressure" series and one "pressure" series. The "differential pressure series' is characterized by a high overload capacity. Can be operated with measuring cells from 250 mbar to 30 bar 1.4 Design and functional principle 1.4.1 Design The device consists of different components depending on what the customer has specified in the order. The possible variants are listed in chapter 12, pg. 123. The rating plate (Figure 1, pg. 13 and Figure 4, pg. 15) with the order number is on the side of the housing. You can determine the optional constructional details and the possible measuring range (physical properties of the built-in sensor element) with the specified number and specifications in chapter 12, pg. 123. 1 Order number 2 Serial number • SIEMENS 0.76101 Karlsruhe • SITRANS P ( 0032 PED:SEP Transmitter for pressure 7MF0034-1EB10-1DA1 Fab. Nr. N1LN11-004711 Us:DC 9-321/ (no, inlr.savel PROF IBUS-PA Mat.:Connoc. Dianne. Filling 1.4404 2 4819 Silikon61 Measuring span : -63 bar Overrange limits : -1 - 100 bar oleetiOniPe$ Figure 1 Example for a rating plate SITRANS P. Series OS III PA A5E00053276-04 13 EFTA01216730 Technical description Opposite it is the license plate (Figure 2, pg. 14 and Figure 4, pg. 15). This contains information about the hardware and firmware versions among other thing. • SIEMENS 0.76131 Kadsruha • SITRANS P '1102 G GEN d NC 7.1/70 U.:DC S 32V I PRODOUS.PA) FIBSOKIEX 1160 Observe ECrod ExaminMIonConiIoaoI • ..85,60°G FVt. 0300.01.01 ION: 02.01 01 • FW: )OOOCYY.ZZ FM: XX.YY.ZZ I I I I I L — — Compatibility identifier I I I I L - - - Terminal board product status L - - — Serial number I I I_ — FW edition — Function range identifier Profile revision (0300 = 3.00) Figure 2 Example of approval plate The electronics housing is made of diecast aluminum or stainless steel precision casting. There is an unscrewable, round cover on the front and rear. The front cover (4, Figure 3, pg. 15) can be designed as a window in order to be able to read measured values directly from the digital display. The inlet (2, Figure 3, pg. 15) to the electrical connection box is located on the side, either left or right. The opening which is not used is sealed by a blanking plug (e.g. 5, Figure 4, pg. 15). The PE conductor terminal (2, Figure 4, pg. 15) is mounted at the front of the housing. The electrical connection box is accessible for power supply and screen when the rear cover (1, Figure 4, pg. 15) is removed. The bottom part of the housing contains the measuring cell with process connection (8, Figure 3, pg. 15). This is secured turning by a locking screw (7, Figure 3, pg. 15). The modular concept of the SITRANS P, Series DS III PA allows the measuring cell and electronics to be exchanged as required. At the top of the housing you can see a plastic cover (3, Figure 3, pg. 15) which can be opened. The input keyboard is beneath this. SITRANS P. Series DS III PA 14 A5E00053276-04 EFTA01216731  Technical description Rating plate Inlet with cable gland Plastic access cover to the input keys Screwable cover, optional with window Digital display Measuring point plate Locking screw Process connection Figure 3 Front view of device SITRANS P, Series DS III PA, pressure series Unscrewable cover for access to electrical connection box PE conductor connection Alternative measuring point plate License plate Blanking plug Figure 4 Rear view of device SITRANS P. Series DS III PA. pressure series SITRANS P. Series DS III PA A5E00053276-04 15 EFTA01216732 Technical description 1.4.2 Mode of operation This chapter describes how the transmitter operates and what protection and safety measures you need to observe. First of all the electronics are described on a Funktionsplanebene (functional level), then the sensors used for the individual measuring modes in the various versions of the device. The process variable to be measured is referred to generally in the following sections as the input variable. 1.4.2.1 Mode of operation of the electronics The input variable provided by the sensor (1, Figure 5) is amplified by an instrument amplifier (2) and converted into a digital signal via an analog-digital converter (3). This is evaluated in a microprocessor (4), its linearity and temperature behavior cor- rected and made available using the isolated interface (5) on the PROFIBUS-PA (7). The measuring cell-specific data of the electronics and the data for transmitter parameterization are stored in two non-volatile memories (6). You can parameterize the transmitter directly at the measuring point with the three input keys (8) and view measuring results, error messages and modes of operation on the digital display (9), which is securely screwed onto the device. You can get the measuring results with status values and diagnosis using the PROFIBUS-PA's cyclical data transmission (see chapter 3.1, pg. 33). Using the acyclical data transmission (see chapter 3.2, pg. 41), you carry out the parameterization and can view all results and error messages. To do this, you require a tool, for example the SIMATIC PDM. SITRANS P. Series DS III PA 16 ASE00053276-04 EFTA01216733  Technical description IIIIIIIIIII 111,1 1,11,1 1,1 1 OOO 00 - Liu 7 Power supply 10 1 Sensor of the measuring cell 2 Instrument ampii er 3 Analog-digital converter* 4 Microcontroller 5 Isolation 6 two non-volatile memories in the measuring cell and in the electronics 7 Proflbus-PA interface 8 three input keys (local operation) 9 Digital display 10 Auxiliary power source 11 DP/PA coupler or link 12 Bus master Figure 5 Transmitter SITRANS P, Series DS III PA, electronics SITRANS P. Series DS III PA A5E00053276-04 17 EFTA01216734 Technical description 1.4.2.2 Pressure The pressure pe is fed in through the process connection (3, Figure 6, pg. 18) of the measuring cell (2). It is passed further through the seal diaphragm (4) and the filling liquid (5) to the silicon pressure sensor (6) and its measuring diaphragm flexes as a result Four piezo-resistors in bridge circuit doped in the measuring diaphragm change their resistance as a result. The change in resistance causes a bridge output voltage proportional to the input pressure. The transmitters with measuring spans 5 63 bar measure the input pressure compared with atmospheric, those with measuring spans z 160 bar compared with a vaccum. CAUTION If the measuring signal fails due to a sensor break, the isolating diaphragms may also be destroyed. In this case,process medium may leak from the threaded collar of the device in pressure transmitters with relative pressure cell (5 63 bar). Reference pressure Measuring cell Process connection Seal diaphragm Filling liquid Silicon pressure sensor Input variable pressure Figure 6 Pressure measuring cell, functional diagram 1.4.2.3 Differential pressure and flow The differential pressure is transmitted via the seal diaphragms (7, Figure 7, pg. 19) and the filling liquid to the silicon pressure sensor (5). On exceeding the measuring limits, the overload diaphragm (6) flexes until one of the seal diaphragms (7) comes into contact with the body of the measuring cell (4) and protects the silicon pressure sensor (5) against overloading. The seal diaphragm is deflected by the resulting differential pressure. Four piezo-resistors in bridge circuit doped in the measuring diaphragm change their resistance as a result. The change in resistance causes a bridge output voltage proportional to the differential pressure. SITRANS P. Series DS III PA 18 A5E00053276-04 EFTA01216735  Technical description Input pressure P, Process flange O-ring Body of the measuring cell Silicon pressure sensor Overload diaphragm Seal diaphragm Filling liquid Input pressure P_ Figure 7 Measuring cell for differential pressure and flow, functional diagram 1.4.2.4 Filling level The input pressure (hydrostatic pressure) acts through the seal diaphragm (10, Figure 8, pg. 19) at the mounting flange hydraulically on the measuring cell. The differential pressure applied at the measuring cell is transmitted via the seal diaphragms (6) and the filling liquid (7) to the silicon pressure sensor (3). On exceeding the measuring limits, the overload diaphragm (5) is deflected until one of the seal diaphragms (6) comes into contact with the body of the measuring cell (4) and protects the silicon pressure sensor (3) against overloading. The measuring diaphragm is flexed by the differential pressure. Four piezo-resistors in bridge circuit doped in the measuring diaphragm change their resistance as a result. The change in resistance causes a bridge output voltage proportional to the differential pressure. Process flange 2 O-ring 3 Silicon pressure sensor 4 Body of the measuring cell 5 Overload diaphragm 6 Seal diaphragm at the measuring cell 7 Filling liquid of the measuring cell 8 Capillary tube with filling liquid of the mounting flange 9 Flange with tube 10 Seal diaphragm at the mounting flange Figure 8 Measuring cell for filling level, functional diagram 1.4.2.5 Absolute pressure from the differential pressure series The absolute pressure is transmitted via the seal diaphragm (6, Figure 9, pg. 20) and the filling liquid (7) to the silicon pressure sensor (3). On exceeding the measuring limits, the overload diaphragm (5) is deflected until the seal diaphragm (6) comes into contact with the body of the measuring cell (4) and protects the silicon pressure sensor (3) against overloading. The pressure difference between the input pressure (pe) and the reference pressure (8) on the low pressure side of the measuring cell flexes the measuring diaphragm. Four piezo-resistors in bridge circuit doped in the measuring diaphragm change their resistance as a result. The change in resistance causes a bridge output voltage proportional to the absolute pressure. SITRANS P. Series DS Ill PA ASE00053276-04 19 EFTA01216736 Technical description Process flange Seal diaphragm at the measuring cell O-ring Body of the measuring cell Silicon pressure sensor Overload diaphragm Filling liquid of the measuring cell Reference pressure Input variable pressure Figure 9 Measuring cell for absolute pressure, functional diagram 1.4.2.6 Absolute pressure from the pressure series The pressure is transmitted via the seal diaphragm (3, Figure 10, pg. 20) and the filling liquid (4) to the absolute pressure sensor (5) and flexes its measuring diaphragm. Four piezo-resistors in bridge circuit doped in the measuring diaphragm change their resistance as a result. The change in resistance causes a bridge output voltage proportional to the input pressure. Measuring cell Pressure connection Seal diaphragm Oil filling Absolute pressure sensor Input variable pressure Figure 10 Measuring cell for absolute pressure from pressure series, functional diagram SITRANS P, Swiss DS III PA 20 ASE00053276-04 EFTA01216737 Communication structure for PROFIBUS PA 2 This chapter describes the mode of operation of the device-specific function blocks with the aid of a graphic block model, which is broken up sequentially into its individual levels. Knowledge of the physical block is assumed: Therefore it is not described in this chapter. 2.1 Block model for recording and processing measured values The functions of the device are divided into blocks for different areas or responsibility (Figure 11). They can be parameterized by acyclic data transfer (see chapter 3.2, pg. 41). Pressure measuring block, absolute pres- sure, differential pres- sure, also filling level, flow and _II Analog input function block PROFIBUS• Counter function block: T Measuring block for Sensor electronics temperature Local operation .- - and display Figure 11 Block connection diagram for recording and processing measured values SITFtANS P. Series OS III PA A5E00053276-04 21 EFTA01216738 Communication structure for PROFIBUS PA 2.1.1 Pressure measuring block The pressure measuring block (Figure 11) carries out adjustments to the sensor. Its initial value is the linearized and temperature-compensated measuring result. For measurement of the filling level and flow, the required conversions take place here. An example is the conversion of an input pressure into level or volume for hydrostatic filling level measurement. The pressure sensor temperature measurement is also processed here and the pressure and temperature limits are constantly monitored. 2.1.2 Electronics temperature measuring block The electronics temperature measuring block (Figure 11) carries out the required temperature measurement functions and monitors the permitted temperature limits. 2.1.3 Analog input function block In the analog input function block (Figure 11), the selected measured value is processed further and is adjusted to the automation task. Example: For a flow measurement, the volume flow needs to be converted into the number of containers filled. The output of this block supplies the measured value and the associated status information to the PROFIBUS. 2.1.4 Counter function block For flow measurement, the volume or mass which has flowed through can be totalled in the counter function block (Figure 11). Its function, therefore, is very similar to that of a water clock. The output of this block supplies the total values and the associated status information to the PROFIBUS. 2.1.5 Local operation and display With local operation (Figure 11), the desired measured value can be set and display