MAN Ax58x PB I_E 1.1
Contents
1. 1 Request_FDL_Status FDL Fieldbus Data Link also known as Layer 2 The Start Delimiter has the value 10 hex This telegram is also sent from an active station always after the GAP time has expired in order to search for new active nodes on the bus 2 Data telegram with variable data length This used in the SRD utility send and request data with acknowledge SD 68 hex 3 Telegram with a fixed data length SD A2 hex 4 Token telegram only between masters SD DC hex 2 3 Configurating a Profibus DP network The interface of the absolute angular encoder is based on the PROFIBUS DP Standard EN 50170 In order to be able to use an absolute angular encoder as a SLAVE with the Profibus DP interface an interface board is required in the control system which acts as PROFIBUS master BUS SYSTEM 3 Encoder profile classification The absolute encoder with Profibus DP interface transfers the process actual value in binary code In addition a preset value can be transferred by setting special bits in the DDLM_Data_Exchange mode Rev 1 0 Pag 13 di 13 Encoder Profibus DP The Profibus Trade Organization PTO has defined encoder profiles named Class 1 and Class 2 A differentiation is made between non parameterizable Class 1 and parameterizable Class 2 absolute encoders When configuring the LIKA ELECTRONIC absolute encoder the user specifies if the encoder should operate as Class 1 or Class 22. Pag 18 di 18 Encoder Profibus DP Insert the green and red cables on the terminals marked with A and B then fix firmly the cables with the terminals The encoder settings are effectuated by the eight DIP switch switch Only the first 7 DIP switch are used because only a setting between 0 and 124 decimals is allowed Each setting can be used by one and only device To activate the terminating line for the last device move to ON the contacts of the two DIP switches see pictures on chap 6 1 1 and 6 1 2 6 4 Assembling instructions Is recommended to do the coupling between the encoder shaft and the exterior shaft of movement transmission with an elastic joint to guarantee the maximum life to the mechanical members of the encoder itself ATTENTION Is keenly recommended to do any machining drilling milling etc on encoder shaft This may cause sever damages of the interior members with immediate expiration of the warranty Our technical commercial personnel is disposable to any request about custom made shaft 6 5 Warnings The following points should be observed Do not drop the angular encoder or subject it to excessive vibration The encoder is a precision device Do not open the angular encoder housing this does not mean that you cannot remove the connection cap If the device is opened and closed again then it can be damaged and dirt may enter the unit The angular encoder shaft must be connected
3. Flashing Parameterizing or configuring error i e the encoder receives configuring or parameterizing data with the incorrect length or inconsistent data for example the total resolution has been set too high Flashing Encoder ready but is not addressed from the master for example an incorrect address was sent Encoder doesn t receive data for a long period of time for example the data line has been interrupted Standard operation in the Data Exchange mode Flashing Rev 1 0 Flashing System blocked Eeprom error Pag 17 di 17 Encoder Profibus DP 6 Installation 6 1 Settings in the Connecting Cover With the DIP switches on connecting side under the connecting cover is possible to set the encoder address and if necessary to activate the terminating resistor see chap 5 1 2 6 1 1 Node address The node station address is simple to set using the rotary switch under the connecting cover Permissible addresses lie between 0 and 127 whereby each one must be unique in the complete system The user can simply remove the connecting cover for installation purposes by releasing two screws on the encoder 6 1 2 Terminating resistor The terminating resistors must be switched in if the encoder is used as the end device The terminating resistors are set using the double dip switches in the connecting cover www lika it e lika Terminating resistor
4. Note Class 1 and Class 2 encoders have nothing to do with Class 1 and Class 2 Masters It is quite possible to use a Class 2 encoder with a Class 1 Master To choose between the different profile versions a GSD File is used The user can select the version that fits his hard and software The GSD file is available from LIKA ELECTRONIC on a floppy disk or in the Internet www lika it The hardware of the absolute encoder apart from the difference between multi and single turn encoders is always the same This allows the same encoder to be used in a wide field of applications 3 1 Class to use If the user needs to know the actual position value and to change the direction of rotation an absolute encoder Class 1 is enough If the user needs also to change resolution of the encoder or to enable a preset value then he have to use a Class 2 encoder 4 Class 1 and Class 2 profile Alus File E211871 The device is to be supplied by a Class 2 Circuit or Low Voltage Limited Energy or Energy Source not exceeding 30 Vde 4 1 Structure of the data when starting up the bus DDLM_Set_Prm mode A differentiation must be made between two statuses when if comes to data transfer On one hand the phase when the system starts up when he angular encoder is parameterized DDLM_Set_Prm mode and on the other hand standard operation DDLMData Exchange mode Some information is transferred at starts up however the preset value is only trans
5. The user can influence this angular range in various ways and therefore adapt the output values to his requirements The output values can be modified as follows 1 Direction of rotation CMP This defines whether the angular encoder counts up when rotating clockwise or when rotating counter clockwise 2 Resolution per revolution RPR Number of steps by which the value increases per revolution 3 Total resolution TR This parameter specifies the highest number which the output position values can assume 4 Preset value PV The user can assign a value to any position of the encoder shaft the preset value The preset value must lie within the total resolution 5 Prog factor A factor x1 x2 can be entered this defines the ratio between the physical resolution x1 and the required resolution x2 The prog factor can be alternatively entered to the value Resolution per revolution 2 2 General information about Profibus Profibus is available in the market with three different versions Profibus FMS Profibus PA and Profibus DP The LIKA ELECTRONIC absolute encoders are designed for use with the DP version The competent contact partner for the Profibus system in general with a broad spectrum of information about the technology manufacturer and suppliers is PROFIBUS Nutzerorganization e V PNO Haid Und Neu Stra e 7 D 76131 Karlsruhe Germany Rev 1 0 Encoder Profibus DP Tel 49 721 96
6. to the shaft to be measured through a suitable coupling This coupling is used to dampen vibrations and imbalance on the encoder shaft and also avoid inadmissible high forces Suitable couplings are available from LIKA ELECTRONIC If the encoder is used in particularly hard environment it is forbidden to use appropriated protective measures Only qualified personnel may commission and operate these devices Qualified personnel have to work according to the safety standard It s forbidden to make any electrical mechanical changes to the encoder Route the connecting cable to the angular encoder at a considerable distance away or completely separated from power cables with their associated and or www lika it e li Ca Encoder Profibus DP noise Completely screen cables must be used for reliable data transfer and good grounding must be provided For fieldBUS interface encoder use only the cables requested for the BUS you are using It is important to use the screen braiding collection devices on connectors which expected it see fieldBUS connectors Cabling establishing and interrupting electrical connections may only be carried out when the equipment is in a no voltage condition Short circuits voltage spikes etc can result in erroneous functions and uncontrolled statuses which can even include severe personnel injury and material damage Before powering up the system check all of the electrical conne
7. 58 590 Fax 49 721 96 58 589 The LIKA ELECTRONIC absolute encoders comply with Profibus DP requirements according with DIN19245 Parts 1 and 3 The integrated Profibus DP interface of the absolute encoder is designed for a maximum data transfer rate of 12 Mbaud The integrated software supports the functions of the official encoder profile for Profibus DP Data is always output in binary code Call telegram DP DP MASTER SLAVES AH Response telegram A basic differentiation is made between the following states when exchanging data 1 Configuring and parameterizing phase DDLM_ Set_Prm This is active when the system starts up 2 DDLM_Data_Exchange mode Standard operation the masters sends an inquiry which the angular encoder responds with the actual position process actual value ty pp svn so LER Ler so pa sa rc Jou Fcs eD oP ea cela tel atc nt MASTER SLAVE jso ue Ler so _ pa sa Fc Joulrcs leo SRD Send and request data with acknowledge Data are sent and received in a message cycle Syn Synchronization Time SA Source Address SD Start Delimiter FC Function Code LE Length DU Data Unit Ler Repeated Length FCS Frame Check Sequence DA Destination Address End Delimiter always 16 hex Pag 12 di 12 www lika it lixa For PROFIBUS DP a differentiation is made between four various telegram types A differentiation is made by the value of the Start Delimiter SD
8. ON OFF 1 2 1 2 The bus has only been correctly terminated if the encoder is mounted to the connecting cover The angular encoder can be commissioned after the address has been set by hardware and the cable terminating resistor has been switched in if required 6 2 To prepare the cable and to connect the screen To connect the cable to the terminal board in the cap the user has to do the following things approximately 55 mm of the bus cable sheath must be removed and approximately 50 mm of the braided screen Approximately 5 mm insulation must be removed from the individual conductors To achieve the highest possible noise immunity the data transmission between different components goes over screened cable The screen should be connected to ground on both ends of the cable In certain cases a compensation current might flow over the screen Therefore a potential compensation wire Is recommended 6 3 Installation procedure For a correct installation of the Profibus DP encoder referred to the following instructions Two cables passing through PG7 carry the power supply Peel the insulated cables then insert the cable with positive voltage on the marked terminal and the ground on the marked terminal BUS lines are brought to the encoder by a couple of PGO9 with braiding collection from each one of them esc a BUS SINET LC2 cable to connect the encoder with the preceding and the following device Rev 1 0
9. ails After the preset value has been received bit 31 is set as acknowledgment and the actual process actual value is immediately returned The procedure is shown below as table Rev 1 0 Encoder Profibus DP M Status bits Master S Slave Bit 31 3029 28 27 26 25 MoS 1 0 0 0 0 0 4 0 S M 1fo oj jo o o o M gt S 00 0 0101 0fJ0 S M 0110 0 01 0 0f0 Data bits 24 0 Required process actual value preset value is transferred here New required process actual value is transferred here Reset to normal mode Pag 16 di 16 New required process actual value is transferred here Note If high precision is required the preset mode should only be executed when the encoder shaft is at a standstill If the shaft moves quickly during this time offsets can occur as even when the preset value is set bus propagation times occur bus delay times 5 Alarm messages using the LEDs in the connection cap The connection cap has two LEDs which optically represent the status of the bus at the angular encoder This red LED is used to display errors and the green LED is used to display the status of the angular encoder Each LED can have one of three conditions OFF ON flashing From the nine combination possibilities six are used to display a special condition www lika it Red LED OFF Status signal possible cause Power supply missing
10. ctions Connections which are not correct can cause the system to function incorrectly and fault connections can result in severe personnel injury and material damage Rev 1 0 Pag 19 di 19 www lika it e li Ca Encoder Profibus DP s alia LIKA Electronic Via S Lorenzo 25 36010 Carr VI Italy Tel 39 0445 382814 Fax 39 0445 382797 Italy eMail info lika it www lika it World eMail info lika biz www lika biz Rev 1 0 Pag 20 di 20 www lika it
11. d as resolution per revolution the output code is no longer in single steps Thus it should be observed that the required resolution does not exceed the resolution of the absolute value encoder defined by the hardware 31 24 23 16 23 to 2 2 162 2 to 2 Measuring per revolution 4 1 6 Total measuring range Using the Total measuring range parameter the user can program the angular encoder so that after a specific number of revolutions it starts to count again at zero Normally this would be 4096 revolutions however using the Total measuring range parameter even shorter periods can be selected The procedure is described below When selecting the total resolution certain rules must be observed These are obtained from the physical principle of the absolute angular encoder also refer to 1 2 The total resolution entered here is the highest output value after which the output values start again at zero Example 100 steps are selected for each revolution total resolution 12 800 and then the angular encoder starts again at zero after 128 revolutions and then counts up to 11 799 For example if 3 700 had been selected then the period after which the output value would repeat itself would be 37 revolutions However this period of 37 revolutions does not fit into the 4096 revolutions which is specified from the hardware and at some point a step occurs This is always the cas
12. e for all pure absolute angular encoders Then if the period length is 4096 revolutions a sequence can repeat Itself after a defined number of revolutions and the angular encoder should start again after this number of revolutions periods If Rev 1 0 Pag 15 di 15 Encoder Profibus DP another period length is required e g the process always repeats itself after 8 revolutions the following rules should be observed 1 If n steps per revolution were selected then the selected total resolution STR cannot cause the periods to be longer than the maximum 4096 revolutions This means that the selected total resolution must be less than 4096 times the number of steps per revolution STR lt 4096 x n If this is not observed then the LEDs in the connecting cover display parameterizing error refer to chap 4 2 The periods i e STR n must be an integer number This must fit an integer number of times integer multiple in 4096 Thus the following equation must apply 4096 STR n 4096 x n STR integer number This function is not monitored No error message is output The value for the selected total measuring range is saved in octets 14 to 17 31 24 23 16 23 to 2 23 to 2 2 to 28 27 to 2 Selected total measuring range in measuring steps Note In order that the resolution can be parameterized to be effective per revolution Class 2 functionality and the scaling
13. ection is defined by bit O in octet 9 Rev 1 0 Pag 14 di 14 Encoder Profibus DP Direction of rotation Octet 9 bit O viewing the shaft Output code Clockwise CW Increasing Counter clockwise CCW Increasing For Class 1 this is the only parameter which can be set 4 1 2 Activating de activating Class 2 functionality Using this switch Class 2 angular encoders can be restricted to the functionality of Class 1 i e the parameterizing capability is disabled Bit 1 in octet 9 is set in order to use the functions of a Class 2 encoder Octet 9 Bit 1 Class 2 functionality Switched out Switched in 4 1 3 Activating de activating Commissioning diagnostics This function has no significance for the LIKA ELECTRONIC absolute encoder 4 1 4 Activating de activating the Scaling function The scaling function enables the resolution per revolution RPR and the selected total resolution STR to be parameterized This switch should always be switched to one if the functions of Class 2 are to be used Octet 9 Bit 3 Scaling function Switched out Switched in www lika it lika 4 1 5 Measuring units per revolution The Measuring units per revolution parameter is used to program the angular encoder so that a required number of steps can be realized referred to one revolution If a value greater than the basic resolution of the absolute value encoder is selecte
14. ferred during normal operation The control system configures the angular encoder when the system starts up i e the encoder profile selected by the user is transferred to the angular www lika it lika encoder also refer to Section 2 Encoder profile classification Depending on the version which was selected the parameter data defined by the user is transferred to the angular encoder parameterization Generally this is realized automatically and the parameters are entered into a mask in the operator control software e g Step 7 However in some cases it is necessary to individually process the bits and bytes Data is transferred according to the Profibus profile as shown in the schematic in the following Table Overview of the significance of the various bits and bytes when the bus starts up OCTET byte No PARAMETER CLASS Reserved for PROFIBUS specific data Code sequence C1 Class2 functionality C2 Commissioning OPTIONAL diagnostics Scaling function C2 control Reserved C2 Reserved C2 Reserved C2 Reserved Measuring units per revolution Total measuring range in measuring units Reserved for future use Manufacturer specific functions OPTIONAL 4 1 1 Code sequence The Code sequence defines the counting direction when the process actual value is output as the shaft rotates clockwise CW or counter clockwise CCW when viewing the shaft The count dir
15. function must be included NOTE If the parameterizing is changed then it maybe necessary to default the earlier set preset in standard operation as they now refer to the modified scaling www lika it lika 4 2 Normal operation DDLM Data Exchange mode This is the normal status when the system is operational When requested to do so the angular encoder sends the actual values to the control system It can then also receive data This is the preset value for Class 2 angular encoders The versions below refer to multi turn versions but can also be considered exactly like single turn encoders 4 2 1 Transferring the process actual value In the standard operating mode MSB 0 bit 31 bit 15 for single turn versions The angular encoder does not change the preset value 4 2 2 Preset value The preset value is the process actual value which should then be output when the axis Is in a certain physical position Using the preset value parameter the value output from the angular encoder is defined at a specific angular position The preset value may not exceed the total resolution parameter The preset value is set after the scaling parameter Resolution per revolution is transferred and Total resolution is set and refers to these scaled quantities The preset value is transferred in the Data_Exchange mode by setting bit 31 It takes less than 40 ms to save the preset so that it is not lost when the power f
16. lika User Manual AS58 PB AS58S PB ASC58 PB AM58 PB AM58S PB AMC58 PB Introduction Serial field bus technology is increasingly meeting with international acceptance in all areas of industrial applications and a wide spectrum of various fieldbus have appeared Profibus is one of the most successful LIKA ELECTRONIC absolute encoders fulfill the requirements of a standard Profibus DP node for a Profibus network This User Guide is intended to help the user to install and use the absolute angular encoders with Profibus interface The GSD File allows the direct input of device parameters in the menu fields of Step7 and other tools used to project Profibus networks We always appreciate feedback improvements and suggestions regarding Se a Summary 1 Safety standards 2 Description and general information 3 Encoder Profile Classification 4 Class 1 and Class 2 Profile 5 Alarm messages using the LEDs in the connection cap 6 Installation 1 Safety standards For electrical connection follow strictly the notes on general catalogue With reference to the directive Rev 1 0 Pag 11 di 11 Encoder Profibus DP 89 336 CEE about electromagnetic compatibility you must respect the following precaution 2 Description and general information 2 1 Description of an absolute encoder We usually make use of absolute encoder when we have to convert the angular position of a shaft into a number This number is then
17. transferred onwards in a digital form The basic principle is that light from a LED is transmitted through a transparent coded disc and the bright dark pattern is converted into digital signals In this manner each angular position corresponds univocally to a sequence of zeros and ones This is the decisive difference to incremental encoders which only sense the change in the angular position but not assign a number to every position If an incremental encoder is rotated when it s in power off condition when the equipment is powered on again the angular position information is lost and it is necessary to home the machine An absolute encoder will always sense position changes even without a power supply available and after the power is switched on again transfers the angular position information to the higher level control system The coded disk allows individual revolutions to be measured standard resolutions available now are 4096 steps 234 and 8192 steps 23 lt per revolution For multi turn versions a special gearbox is integrated in the absolute encoder This system can www lika it lika sense up to 4096 revolutions This is a configuration non available with an absolute assignment of the angular range of 4096 steps revolution x 4096 revolutions the total number of steps is 16 777 215 These values are absolute i e there is an absolute zero point and after 4096 revolutions the same values are repeated
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