SMA5 User's guide in English
Contents
1. Error and fault diagnostics on page 12 MAN SMA5 E 1 5 odt 14 www lika it www lika biz This page intentionally left blank pO 10 QtBue 0 0 0 0 0 0 00 1 11 User s guide updated 2 12 User s guide updated 3 13 Section 5 SSI interface updated e u ee 1 User s guide updated section 5 SSI interface updated General review section 3 Mounting 5 1 instructions updated 1 0 A T2 1 3 1 4 D Dispose separately s li a Lika Electronic Via S Lorenzo 25 36010 Carr VI Italy Tel 39 0445 806600 Fax 39 0445 806699 Italy eMail info lika it www lika it World eMail info lika biz www lika biz2. RS 422 standard The output code can be either Binary or Gray see the order code 5 2 LSB right aligned protocol LSB right aligned protocol allows to right align the bits beginning from MSB most significant bit to LSB least significant bit LSB is then sent at the last clock cycle Transmitted bits are always 25 the sensor uses a variable number of bits according to resolution Unused bits are set to O zero and lead the data word Model Resolution Length of the word iod SMA5 GA 100 0 1 mm 25 bits 16 bits 65535 SMA5 GA 50 0 05 mm 25 bits 17 bits 131071 SMA5 GA 10 0 01 mm 25 bits 19 bits 524287 SMA5 GA 5 0 005 mm 25 bits 20 bits 1048575 he output code of the sensor is GRAY The length of each information is equal to the resolution 0 1 mm 0 005 mm Position information structure SMAS GA 100 bits 25 17 16 1 SMA5 GA 50 bits 25 18 17 1 SMAS GA 10 bits 25 20 19 1 1 MAN SMAS5 E 1 5 odt 10 www lika it www lika biz lixa SMAS WARNING he position value issued by the sensor is expressed in pulses to convert the pulses into a metric measuring unit you must multiply the number of detected pulses by the resolution Example 1 SMA5 GA 5 detected pulses 123 position value 123 5 2 615 um 0 615 mm 5 3 Recommended transmission rates The SSI interface has a frequency of data transmission rang
3. in Figure 1 the sensor is travelling too fast the power supply is not as required NOTE When the LED is off this means that the sensor is working properly and the absolute position is output correctly For further information refer also to section 8 Troubleshooting on page 14 MAN SMA5 E 1 5 odt 12 www lika it www lika biz lixa SMAS 7 Maintenance he magnetic measurement system does not need any particular maintenance anyway it has to be handled with the utmost care as any delicate electronic equipment From time to time we recommend the following operations e periodically check the soundness of the structure and make sure that there are no loose screws tighten them if necessary e check the gap between the sensor and the magnetic scale all along the whole measuring length Wear of the machine may increase the tolerances e the surface of the magnetic scale has to be regularly cleaned using a soft and clean cloth to remove dust chips moisture etc MAN SMA5 E 1 5 odt 13 www lika it www lika biz lixa SMAS 8 Troubleshooting he following list shows some typical faults that may occur during installation and operation of the magnetic measurement system Fault The system does not work no pulse output e he scale and or the sensor are not installed properly the active surface of the scale does not match the sensitive part of the sensor For correct installation please refer to section 3 Mounting instr
4. must first set the Counting direction and then zero set the encoder position MAN SMA5 E 1 5 odt 8 www lika it www lika biz lixa SMAS 5 SSI interface Order code SMA5 GA 5 1 SSI Synchronous Serial Interface SSI the acronym for Synchronous Serial Interface is a synchronous point to point serial 2C interface engineered for unidirectional data SYNONAONOUS SERIAL INTERMCE transmission between one Master and one Slave Developed in the first eighties it is based on the RS 422 serial standard Its most peculiar feature is that data transmission is achieved by synchronizing both the Master and the Slave devices to a common clock signal generated by the controller in this way the output information is clocked out at each controllers request Furthermore only two pairs of twisted wires are used for data and clock signals thus a six wire cable is required he main advantages in comparison with parallel or asynchronous data transmissions are e less conductors are required for transmission e less electronic components e possibility of insulting the circuits galvanically by means of optocouplers e high data transmission frequency e hardware interface independent from the resolution of the absolute encoder Furthermore the differential transmission increases the noise immunity and decreases the noise emissions It allows multiplexing from several encoders thus process controls are more reliable with simplified line design and
5. also known as Complementary The standard counting direction is to be intended with sensor moving as indicated by the arrow in Figure 1 This input allows to reverse the counting direction In other words it allows the count up when the sensor moves in the MAN SMAS5 E 1 5 odt 7 www lika it www lika biz lixa SMAS reverse of the standard direction i e in the opposite direction to the one shown by the arrow in Figure 1 Connect the input to OVDC if not used When the Counting direction input is connected to OVDC the position information Increases when the sensor moves according to the arrow in Figure 1 When the Counting direction input is connected to VDC the position information increases when the sensor moves in reverse of the standard direction i e in the opposite direction to the one shown by the arrow in Figure 1 WARNING A zero setting operation Is required after setting the counting direction 4 4 Zero setting The output value can be set to zero reset by means of an external signal sent by a PLC or other device The internal microprocessor uses this signal to zero set the position information Thus the position information will be O in the point where the operation is performed Connect the Zero setting input to OVDC if not used To zero set the value connect the input to VDC for 100 us at least then disconnect VDC Normally voltage must be at OVDC or floating The reset must be performed when the sensor is in stop You
6. easier data management Data transmission is carried out as follows At the first falling edge of the clock signal 1 the logic level changes from high to low the absolute position value is stored while at the following rising edge 2 the transmission of data information begins starting from the MSB CLOCK At each change of the clock signal and at each subsequent rising edge 2 one bit is clocked out at a time up to LSB so completing the data word transmission The cycle ends at the last rising edge of the clock signal 3 This MAN SMAS5 E 1 5 odt 9 www lika it www lika biz lixa SMAS means that up to n 1 rising edges of the clock signals are required for each data word transmission where n is the bit resolution for instance a 13 bit encoder needs 14 clock edges If the number of clocks is greater than the number of bits of the data word then the system will send a zero low logic level signal at each additional clock zeros will either lead LSB ALIGNED protocol or follow MSB ALIGNED protocol or lead and or follow TREE FORMAT protocol the data word After the period Tm monoflop time having a typical duration of 12 usec calculated from the end of the clock signal transmission the encoder is then ready for the next transmission and therefore the data signal is switched high he clock signal has a typical logic level of 5V the same as the output signal which has customarily a logic level of 5V in compliance with
7. ersonal and or the environment damage e high current voltage and moving mechanical parts can cause serious or fatal injury e warning Do not use in explosive or flammable areas failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the equipment e Lika Electronic assumes no liability for the customer s failure to comply with these requirements 1 2 Electrical safety e Turn OFF power supply before connecting the device e connect the unit according to the explanation in the section 4 Electrical connections e the wires of unused signals must be cut at different lengths and insulated singularly e in compliance with 2004 108 EC norm on electromagnetic compatibility following precautions must be taken 4 before handling and installing the equipment discharge electrical charge from your body and tools which may come in touch with the device power supply must be stabilized without noise install EMC filters on device power supply if needed T or P type LC filters are often adequate always use shielded cables twisted pair cables whenever possible avoid cables runs longer than necessary avoid running the signal cable near high voltage power cables e g drive cables install the device as close as possible to the electronic control unit mount the device as far as possible from any capacitive or inducti
8. ing between 100 kHz and 1 5 MHz The CLOCK signal and DATA signal comply with the EIA standard RS 422 The clock frequency baud rate depends on the length of the cable and must comply with the technical information reported in the following table Cable length 400 kHz 300 kHz lt 200 kHz 100 kHz he time interval between two Clock sequence transmissions must be at least 30 us Tp gt 30 us Clock UU Lb UL MAN SMAS E 1 5 0d T www lika it www lika biz lixa SMAS 6 Error and fault diagnostics In case of wrong alignment between the sensor and the magnetic scale at power on or during operation the following errors may occur e the LED lights up when switching on the system there is a wrong alignment position value O zero is transmitted until valid data is detected please install the sensor properly as soon as the sensor is aligned correctly the LED switches off e the LED lights up during operation the last valid position is frozen kept in memory until the next valid position is detected on the scale 6 1 Diagnostic LED When the LED lights up it indicates that an error is active such as for instance an incorrect alignment between the sensor and the scale the gap between the sensor and the scale is out of tolerance see Figure 2 the sensor is not installed properly the sensor or the scale are installed upside down the sensor is installed in the opposite direction to the one shown
9. ka it www lika biz lixa SMAS Distance from the scale Lateral deviation Roll 0 1 1 0mm ps z lt 3 i pnis bad d Lil ER ut rt 0 5 mm Tilt lt 1 e Figure 2 WARNING After having installed the sensor on the magnetic scale a zero setting operation is compulsorily required The zero setting operation is further required every time either the sensor or the scale is replaced For further information refer to page 8 MAN SMA5 E 1 5 odt 6 www lika it www lika biz lixa SMAS 4 Electrical connections WARNING Electrical connection has to be carried out by qualified personnel only with power supply disconnected and mechanical parts compulsorily in stop WARNING If wires of unused signals come in contact irreparable damage could be caused to the device Please insulate them singularly Connections 4 1 M8 cable specifications Model LIKA HI FLEX M8 cable Wires 6x0 14 mm 2 x 0 22 mm Shield tinned copper braid Outer diameter 5 3 5 6 mm 0 21 0 22 Conductor resistance 6x 148 O km 2 x 90 O km Minimum bending radius x 7 5 4 2 Ground connection Minimize noise by connecting the shield and or the sensor to ground Make sure that ground is not affected by noise The connection point to ground can be situated both on the device side and on users side The best solution to minimize the interference must be carried out by the user 4 3 Counting direction This input is
10. lixa SMAS User s guide SMA5 Description This guide is designed to describe the SMAB series sensors These sensors are designed to measure linear displacements in industrial machines and automation systems The measurement system includes a magnetic scale and a magnetic sensor with conversion electronics The scale is magnetized with alternating magnetic north south poles The poles are coded thus the system provides an absolute information As the sensor is moved along the magnetic scale it detects the displacement and yields an absolute position information through the SSI interface he sensor has to be paired with the MTA5 type magnetic scale SYNCHRONOUS SERIAL INTERFACE Table of contents 1 Safety summary 2 Identification 3 Mounting instructions 4 Electrical connections 5 SSI interface 6 Error and fault diagnostics 7 Maintenance 8 Troubleshooting MAN SMA5 E 1 5 odt 1 www lika it www lika biz lixa SMAS 1 Safety summary 1 1 Safety e Always adhere to the professional safety and accident prevention regulations applicable to your country during device installation and operation installation and maintenance operations have to be carried out by qualified personnel only with power supply disconnected and stationary mechanical parts e device must be used only for the purpose appropriate to its design use for purposes other than those for which it has been designed could result in serious p
11. nsor and the magnetic scale from jamming Make sure the mechanical installation meets the system s requirements of distance planarity and parallelism between the sensor and the scale indicated in Figure 2 all along the whole measuring length he Figure below shows how the sensor and the scale must be installed the arrow indicates the standard counting direction increasing count see on page 7 WARNING he system cannot work if mounted otherwise than illustrated in the Figure below MAN SMAS5 E 1 5 odt 4 www lika it www lika biz lixa SMAS 3 3 Mounting the sensor 2 x M5 cylinder head screws 25 mm min long Mounting direction Figure 1 Make sure the mechanical installation complies with the system requirements concerning distance planarity and parallelism between the sensor and the scale Avoid contact between the parts Sensor is fixed by means of two M5 25 mm min long cylinder head screws inserted in the provided holes Recommended minimum bend radius of the cable R 42 mm The allowed gap between the sensor and the scale is 0 1 mm 1 0 mm 0 004 0 04 Do not use the cover strip it would cause an excessive gap between the sensor and the scale surface WARNING Make sure the mechanical installation complies with the system requirements concerning distance planarity and parallelism between the sensor and the scale as shown in Figure 2 all along the whole measuring length MAN SMA5 E 1 5 odt 5 www li
12. or and the magnetic scale from jamming 2 Identification Device can be identified through the ordering code and the serial number printed on the label applied to its body Information is listed in the delivery document too Please always quote the ordering code and the serial number when reaching Lika Electronic for purchasing spare parts or needing assistance For any information on the technical characteristics of the product refer to the technical datasheet Warning devices having ordering code ending with Sxxx may have mechanical and electrical characteristics different from Standard and be supplied with additional documentation for special connections Technical Info MAN SMAS5 E 1 5 odt 3 www lika it www lika biz lixa SMAS 3 Mounting instructions WARNING Installation has to be carried out by qualified personnel only with power supply disconnected and mechanical parts compulsorily in stop 3 1 Overall dimensions 20 20 3 2 Magnetic scale The sensor has to be paired with the MTA5 type magnetic scale only For detailed information on the MIA5 type scale and how to mount it refer to the Specific technical documentation Install the unit providing protection means against waste especially swarf as turnings chips or filings should this not be possible please make sure that adequate cleaning measures as for instance brushes scrapers jets of compressed air etc are in place in order to prevent the se
13. uctions on page 4 he diagnostic LED is lit e A magnetic part or a protection surface is interposed between the sensor and the scale Only non magnetic materials are allowed between the sensor and the scale he diagnostic LED is lit e Installation does not comply with the tolerance gap between the sensor and the scale indicated in this guide the sensor hits the surface of the scale or is too far from it Check whether the sensor sensitive part is damaged e Ihe sensor has been damaged by short circuit or wrong connection Fault he measured values are either inaccurate or not provided in the whole length e he gap between the sensor and the scale is not respected all along the whole measuring length See the section 3 Mounting instructions on page 4 e he sensor is not installed properly on the scale See the section 3 Mounting instructions on page 4 e he connection cable runs near high voltage cables or the shield is not connected properly Check the earthing point e he frequency of the Master clock is set too high or too low and the transmission cannot be synchronized correctly See the section 5 SSI interface on page 9 e A section of the magnetic scale has been damaged mechanically or magnetically along the measuring length e he measuring error is caused by a torsion in the machine structure Check parallelism and symmetry in the movement of the machine For further information refer also to the section 6
14. ve noise source shield the device from noise source if needed mount the device as far as possible from the inverter if installed in the machine shield the device if needed to guarantee a correct working of the device avoid using strong magnets on or near by the unit minimize noise by connecting the cable shield and or the sensor to ground Make sure that ground is not affected by noise The connection point to ground can be situated both on the device side and on user s MAN SMAS5 E 1 5 odt 2 www lika it www lika biz lixa SMAS side he best solution to minimize the interference must be carried out by the user 1 3 Mechanical safety Install the device following strictly the information in the section Errore sorgente del riferimento non trovata e mechanical installation has to be carried out with stationary mechanical parts e do not disassemble the unit e do not tool the unit e delicate electronic equipment handle with care do not subject the device to knocks or shocks e protect the unit against acid solutions or chemicals that may damage it e respect the environmental characteristics of the product e we suggest installing the unit providing protection means against waste especially swarf as turnings chips or filings should this not be possible please make sure that adequate cleaning measures as for instance brushes scrapers jets of compressed air etc are in place in order to prevent the sens
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