Manual. MOVIAXIS MX Multi-Axis Servo Inverter Virtual Encoder Technology Function. Edition 05/ / EN

Transcription

1 Gearmotors \ Industrial Gear Units \ Drive Electronics \ Drive Automation \ Services MOVIAXIS MX Multi-Axis Servo Inverter Virtual Encoder Technology Function Edition 05/ / EN Manual

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3 Contents Contents 1 Notes Explanation of symbols Safety notes System Description General information Description of Functions Basic functions of the virtual encoder Block circuit diagram of the virtual encoder Jerk limitation Extended position output Control via Data Distribution Buffer (DDB) Type and version ID of a data structure in the DDB Parameter Description Operating Modes "Absolute" positioning mode "Relative" positioning mode "Modulo absolute positive" positioning mode "Modulo absolute positive" positioning mode "Modulo absolute negative" positioning mode "Modulo relative negative" positioning mode "Modulo absolute short" positioning mode "Modulo relative short" positioning mode Endless operating modes "Continuous Circular / Continuous Modulo" Error Messages Problem description Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 3

4 1 Notes Explanation of symbols 1 Notes 1.1 Explanation of symbols Always observe the safety and warning instructions in this documentation. Electrical hazard Possible consequences: Severe or fatal injuries. Hazard. Possible consequences: Severe or fatal injuries. Hazardous situation Possible consequences: Slight or minor injuries. Harmful situation Possible consequences: Damage to the unit and the environment. Tips and useful information. 1.2 Safety notes Preliminary information The following safety notes apply to MOVIAXIS in connection with the Virtual Encoder technology function. Please also observe the supplementary safety notes in the individual sections of this manual General safety notes The MOVIAXIS multi-axis servo inverter with the Virtual Encoder technology function must only be installed and taken into operation by electrical specialists observing the relevant accident prevention regulations and MOVIAXIS operating instructions. 4 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

5 Notes Safety notes 1 Read through this manual carefully before you start to install and startup MOVIAXIS with the Virtual Encoder technology function. This manual does not replace the detailed MOVIAXIS operating instructions. A requirement of fault-free operation and the possibility of any rights to claim under guarantee is that you observe the information in the MOVIAXIS documentation. Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 5

6 2 System Description General information 2 System Description 2.1 General information The virtual encoder is a configurable software counter, which can be used for simulating the position signal of a real axis. It enables synchronous travel of several axes, e.g. for electronic cam and synchronous operation applications. For this purpose, the virtual encoder offers different operating modes: Positioning modes Infinite operation VEncoderMode: (parameter no. 2) Operating mode 1 Absolute 2 Relative 3 Modulo Absolute Positive 4 Modulo Relative Positive 5 Modulo Absolute Negative 6 Absolute Relative Negative 7 Modulo Absolute Short 8 Modulo Relative Short 9 Continuous Circular 10 Continuous Modulo For more detailed information on the individual modes, please refer to sec. 5 "Operating Modes". 6 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

7 Description of Functions Basic functions of the virtual encoder 3 3 Description of Functions 3.1 Basic functions of the virtual encoder Similar to a real axis, the virtual encoder requires the user to specify values, e.g. for position and speed, which the encoder is going to use. The user can stop and start the virtual encoder at any time using the feedforward enable. The axis that includes the virtual encoder can also synchronize to the virtual encoder position. The position values of the virtual encoder can be transferred to other axes. 3.2 Block circuit diagram of the virtual encoder VelocityMaxPos VelocityMaxNeg VelocitySetpoint AccelerationMax DecelerationMax JerkMax Internal position profile generator PositionModulo PositionExtended Position Velocity Acceleration PositionSetpoint Strobe FeedEnable VEncoder controller UseFeedEnable UseStrobe VEncoderMode The input and output parameter for the virtual encoder are described in detail in sec. 4 "Parameter Description". Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 7

8 3 Description of Functions Jerk limitation 3.3 Jerk limitation The virtual encoders operates with an internal, jerk limited profile generator. Jerk limitation is realized via a mean value filter. The determination is based on the jerk time. The jerk time is calculated from the parameters "AccelerationMax / DecelerationMax" and "JerkMax", which are set by the user. ( ) max AccelerationMax, DecelerationMax JerkTime [] s = 1 JerkMax 2 min s 1 min s The jerk time is calculated anew when the virtual encoder is switched on and when a different value is specified for "JerkMax". Jerk time values are internally limited to minimum "0 s" and maximum "1 s". If "JerkMax" or the calculated jerk time is zero, the jerk limitation is deactivated and the profile generator operates with linear ramps. a j=0 t a j=0 t1 t t 1 Jerk time 8 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

9 Description of Functions Extended position output Extended position output For electronically synchronized axes (e.g. for phase-synchronous operation, egear, electronic cam) it can be useful to work with a higher position resolution. The higher position resolution has a positive effect on the speed quality of the motor. The variable "PositionExtFactor" can be used to specify a factor for extending the internal position of the virtual encoder: PositionExtended = PositionExtFactor ( internal position) 3.5 Control via Data Distribution Buffer (DDB) The user interface for the Virtual Encoder technology function is implemented using the connected data memory Data Distribution Buffer (DDB). The DDB consists of 4096 indices with a data width of 32 bit and is used as a parameter interface. Each technology function using the DDB as user interface has the parameter "Start address". Starting with this parameter, the data structure of the corresponding technology function is stored in the DDB. In addition, the function is activated or deactivated with this parameter: Start address = 0 Technology function deactivated. Start address 0 This value determines the start address of the first parameter in the DDB ( ) and activates the "Virtual Encoder" technology function. Write and read access to the DDB is via indexed access with 32 main indexes and 128 subindexes. Main index Subindex DDB(0) DDB(1) DDB(2)... DDB(127) DDB(128) DDB(129) DDB(130)... DDB(255) DDB(256) DDB(257) DDB(258)... DDB(383) DDB(3968) DDB(3969) DDB(3970)... DDB(4095) Please note for read and write access to the DDB that all setpoint and actual values in the DDB are interpreted by MOVIAXIS using the resolution of the system units. User units, if defined, are not considered here. Resolution of system units: Position [65536 inc / motor revolution] Speed n [ /min] Acceleration / Deceleration [0.01 1/(min s)] Jerk [1/(min s 2 )] Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 9

10 3 Description of Functions Type and version ID of a data structure in the DDB 3.6 Type and version ID of a data structure in the DDB Each data structure in the DDB is clearly identified by a type and version ID and the specified structure length: Length: Type_Version: Specifies the length of the data structure Minor Version: Identification of additional functions Major Version: Identification of the functionality Type: Type of data structure Type 200: Data structure for FCB17 egear Type 300: Data structure for physical encoder Type 400: Data structure for virtual encoder Type 800: Data structure for position setpoint generator 10 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

11 Parameter Description Type and version ID of a data structure in the DDB kva i P f n Hz 4 4 Parameter Description Category No. Symbolic name Meaning/function Access 0 Length Length of the virtual encoder block: 38 variables R Management 1 Type_Version Bit : Minor Version Bit : Major Version Bit : Type: 400 (400 = virtual encoder) Mode 2 VEncoderMode VEncoderMode is used to set the operating mode of the virtual encoder (for more information on operating modes, refer to sec. 5). Write a value between 1 and 10 to select one of the following operating modes: 1. = Absolute 2. = Relative 3. = Modulo Absolute Positive 4. = Modulo Relative Positive 5. = Modulo Absolute Negative 6. = Modulo Relative Negative 7. = Modulo Absolute Short 8. = Modulo Relative Short 9. = Continuous Circular 10. = Continuous Modulo W Control 3 VEncModeControl Bit 0 SetState 0 1 edge initializes the position and velocity of the virtual encoder with the values of "PositionIni" and "VelocityIni". R/W Bit 1 UseFeedEnable = 0 : Feedforward enable is not used = 1 : Feedforward enable is used Bit 2 FeedEnable Use "FeedEnable" to activate or deactivate the feedforward enable. The "FeedEnable" variable only has an effect if "Use- FeedEnable" = 1. If "UseFeedEnable" = 0, feedforward is always enabled = 0 : no feedforward enable, i.e. the virtual encoder is not operating = 1 : Feedforward enable, the virtual encoder operates with the set values for v and a Bit 3 UseStrobe = 0 : The target position is transferred without 0 1 edge at "VEncoderModeControl" / bit 4 (strobe) = 1 : The target position is transferred only with an 0 1 edge at "VEncoderModeControl" / bit 4 (strobe) Bit 4 Strobe 0-1 edge for transferring the target position. Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 11

12 4 kva i P f n Hz Parameter Description Type and version ID of a data structure in the DDB Category No. Symbolic name Meaning/function Access Status 4 VEncStatus In bits 0-4, the setting of "VEncoderModeControl" is reflected. Bit 0 SetState see also VEncModeControl / bit 0 Bit 1 UseFeedEnable see also VEncModeControl / bit1 Bit 2 FeedEnable see also VEncModeControl / bit 2 Bit 3 UseStrobe see also VEncModeControl / bit 3 Bit 4 Strobe see also VEncModeControl / bit 4 Bit 8 TargetReached = 0 : Target position not reached yet = 1 : Target position reached R 12 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

13 Parameter Description Type and version ID of a data structure in the DDB kva i P f n Hz 4 Category No. Symbolic name Meaning/function Access Value 5 PositionSetpoint Target position for all modes of the virtual encoder, except for "Continuous" Resolution: inc / motor revolution 6 VelocitySetpoint Setpoint speed; resolution: [ /min]; e.g /min /min 7 PositionModulo Current modulo position of the virtual encoder R 8 PositionExtended 9 Position 10 Velocity 11 Acceleration 12 VelocityMaxPos 13 VelocityMaxNeg 14 AccelerationMax 15 DecelerationMax 16 JerkMax 17 PositionIni 18 VelocityIni 19 PositionExtFactor 20 ModuloMax The current position of the virtual encoder multiplied with "PositionExt- Factor" "PositionExtended" = "PositionExtFactor" "Position" Actual position of the virtual encoder Resolution: inc / motor revolution Current velocity of the virtual encoder Resolution [ /min]; e.g.: /min /min Current acceleration of the virtual encoder ; Resolution [0.01 1/min s]; e.g.: /min s /min s Maximum positive positioning velocity of the virtual encoder; Resolution [ /min]; Input 0 Ineffective in the "endless" operating modes Maximum negative positioning velocity of the virtual encoder; Resolution [ /min]; Input 0 Ineffective in the "endless" operating modes Maximum acceleration of the virtual encoder Resolution [0.01 1/min s] Input > 0 Maximum deceleration of the virtual encoder Resolution [0.01 1/min s] Input > 0 Maximum jerk of the virtual encoder Resolution [1/(min s²)] Initialization value that is written to the current position ("Position") when there is a 0-1 edge at "VEncoderModeControl" / bit 0. Initialization value that is written to the current velocity ("Velocity") with "VEncoderModeControl" / bit 0. Multiplier for the extended current position of the virtual encoder "PositionExtended" = "PositionExtFactor" "Position" Value range: Maximum modulo value Value range: ModuloMin Minimum modulo value Value range: Reserved Reserved Reserved --- W R R R R W W W W W W W W W W Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 13

14 5 kva i P f n Hz Operating Modes "Absolute" positioning mode 5 Operating Modes 5.1 "Absolute" positioning mode In this operating mode, absolute positioning is enabled if a suitable target position is specified. When a new target position specification is detected and the feedforward is enabled, the "PositionSetpoint" value is read and transferred to "DestinationPosition" as the new target. Example: The actual position is inc and a target position of inc is specified. The profile generator now runs from inc via inc to =2-1 Counter value 2 32 Actual position Target position Axis position = "Relative" positioning mode When a new relative target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is added to "DestinationPositionOld" and the result is written to "DestinationPosition": DestinationPosition = PositionSetpoint + DestinationPositionOld The memory of the last relative target position "Position Old" is then overwritten with the new relative target position "PositionSetpoint". In this operating mode, endless positioning is possible. Example: Actual position = Relative target position = Target position = = Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

15 Operating Modes "Modulo absolute positive" positioning mode kva i P f n Hz "Modulo absolute positive" positioning mode When a new absolute modulo target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is read. The value of "PositionOld" is then subtracted from "PositionSetpoint". If this difference is negative, "ModuloValue" (ModuloValue = -ModuloMax - ModuloMin) is added to obtain a positive positioning distance. This value is then added to "DestinationPositionOld". The sum of this is written to the variable "DestinationPosition". If the absolute modulo target position specification "PositionSetpoint" is smaller than "ModuloMin" or larger than "ModuloMax", error 38 is triggered. ModuloMax-1 Counter value 2 32 Axis position ModuloMin In this operating mode, the virtual encoder can only count in the positive direction. Example: If the virtual encoder is in position 1000 and receives the target specification 0, it will travel via "ModuloMax -1" and "ModuloMin" to "Modulo absolute positive" positioning mode When a new modulo target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is added to the "DestinationPositionOld" value and the result is written to the "DestinationPosition" variable. The memory of the last relative modulo target position "PositionOld" is then overwritten with the new relative modulo target position "PositionSetpoint". If the relative modulo target position specification "PositionSetpoint" becomes negative, error 38 is triggered. It is permitted to specify relative modulo target position that exceed the value of "ModuloMax". Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 15

16 5 kva i P f n Hz Operating Modes "Modulo absolute negative" positioning mode 5.5 "Modulo absolute negative" positioning mode When a new modulo target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is read. The value of "PositionOld" is then subtracted from "PositionSetpoint". If the difference is positive, the value is subtracted from "ModuloValue" (ModuloValue = ModuloMax - ModuloMin) to obtain a negative positioning distance. To this value, the value of "DestinationPositionOld" is added. The sum of this is written to "DestinationPosition". The memory of the last absolute modulo target position "PositionOld" is then overwritten with the new absolute modulo target position "PositionSetpoint". If the absolute modulo target position specification "PositionSetpoint" is smaller than "ModuloMin" or larger than "ModuloMax", error 38 is triggered. In this operating mode, the position profile generator of the virtual encoder only operates in the negative direction. If, for example, the position profile generator stands at "-1000" and receives the value"0" as target, it will travel in the negative direction via "ModuloMin" and "ModuloMax" to "0". ModuloMax-1 Counter value 2 32 Axis position ModuloMin 5.6 "Modulo relative negative" positioning mode When a new relative modulo position specification is detected and feedforward is enabled, the "PositionSetpoint" value is added to the "DestinationPositionOld" value and the result is written to the "DestinationPosition" variable. The memory of the last relative modulo target position "PositionOld" is then overwritten with the new relative modulo target position "PositionSetpoint". If the relative modulo target position specification "PositionSetpoint" is positive, error 38 is triggered. 16 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

17 Operating Modes "Modulo absolute short" positioning mode kva i P f n Hz "Modulo absolute short" positioning mode When a new absolute modulo target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is read. The value of "PositionOld" is then subtracted from "PositionSetpoint". Then, an alternative value "Xa" is calculated for the difference "X". If the value of "X" is negative, the value of "ModuloValue" (ModuloValue = ModuloMax - ModuloMin) is added to obtain a positive alternative positioning distance "Xa". Now, the absolute values of "X" and "Xa" are compared and the value with the smaller absolute value is chosen. To this value, the value of "DestinationPositionOld" is added. The sum is written to "DestinationPosition" and transferred to the position profile generator. The memory of the last absolute modulo target position "PositionOld" is then overwritten with the new absolute modulo target position "PositionSetpoint". If the absolute modulo target position specification "PositionSetpoint" is smaller than "ModuloMin" or larger than "ModuloMax", error 38 is triggered. In this operating mode, the position profile generator of the virtual encoder can operate in both positive and negative direction. This enables positioning in both directions. Example: The profile generator stands at "ModuloMax -5" and "ModuloMin +5" is specified as a target. Then the position profile generator travels via "ModuloMax -1" and "ModuloMin" to "ModuloMin +5". ModuloMax-1 Counter value 2 32 Axis position 5.8 "Modulo relative short" positioning mode When a new relative modulo target position specification is detected and feedforward is enabled, the "PositionSetpoint" value is added to the "DestinationPositionOld" value and the result is written to the "DestinationPosition" variable. The memory of the last relative modulo target position "PositionOld" is then overwritten with the new relative modulo target position "PositionSetpoint". In this operating mode, both positive and negative modulo target positions can be specified. The modulo target position specifications can also have the following values: Value > ModuloMax, Value < ModuloMin. Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 17

18 5 kva i P f n Hz Operating Modes Endless operating modes "Continuous Circular / Continuous Modulo" 5.9 Endless operating modes "Continuous Circular / Continuous Modulo" In the "Continuous Mode", the target position of the internal profile generator is always moved further in the positive or negative direction depending on the sign of the velocity setpoint value ("VelocitySetpoint"), so that it is never reached. The maximum and the minimum positioning velocity of the internal profile generator is set to the value of "VelocitySetpoint". For acceleration, the value of "AccelerationMax" is effective, for deceleration, the value of "DecelerationMax" is used. The target position of the internal profile generator is moved very far in the positive or negative direction depending on the sign of "VelocitySetpoint". This ensures that, when switching from positioning mode to endless operation, no position or velocity step change occurs. The jerk limitation function calculates the appropriate limitation from the values of "AccelerationMax", "DecelerationMax" and "JerkMax". If the value of "JerkMax" = 0, the jerk limitation is deactivated. Positioning is performed with linear velocity ramps. "Continuous Circular" operating mode In the "Continuous Circular" operating mode, "SetState" can be used to perform an initialization. For this purpose, the value of "Position" is set once to the value of "PositionIni". "Continuous Modulo" operating mode If an initialization with "SetState" is performed in the "Continuous Modulo" operating mode, "Position" and "PositionModulo" are set once to the value of "PositionIni". Changing the operating mode When changing from the operating mode "Continuous Circular" or "Continuous Modulo" to the operating mode "ModuloAbsolutePositive" positioning or "ModuloAbsoluteNegative" positioning or "ModuloAbsoluteShort" positioning the target position of the internal profile generator is calculated. The calculation is based on the current velocity of the virtual encoder and the value of the "PositionSetpoint" parameter and enables travelling to the target position. 18 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

19 Operating Modes Endless operating modes "Continuous Circular / Continuous Modulo" kva i P f n Hz 5 If the direction of rotation is correct when the operating mode is changed, non-permitted repositioning is prevented. If the drive would stop beyond the "PositionSetpoint" position, an additional modulo cycle is added. However, this will only work if the current velocity is positive when changing to "ModuloAbsolutePositive" or negative when changing to "ModuloAbsoluteNegative". For all modulo operating modes applies that "ModuloMax" cannot be travelled to. "ModuloMin", however, can be reached. This means: "ModuloValue" = "ModuloMax" - "ModuloMin". Example: If "ModuloValue" is to be " ", "ModuloMin" can be set to "0" and "ModuloMax" to " ". The modulo position is then within the range of " ". If a new target position is specified when the operating mode is changed, this position is immediately travelled to. Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter 19

20 6 kva i P f n Hz Error Messages Problem description 6 Error Messages 6.1 Problem description Errors occurring during the operation of the virtual encoder are shown as "Error 38: Error in one technology function" (main error). The sub error code offers more information on the cause of the error. Main error 38 Sub error code Problem Response Remedy 100 Data structure exceeds DDB limit. Display only Check structure in the DDB 101 Incorrect virtual encoder block type Display only Check structure in the DDB 102 Virtual encoder block version incompatible with firmware 103 Ramp parameters are invalid Display only Virtual encoder stops; Velocity = 0 Acceleration = ModuloMin ModuloMax 106 Target specification not within permitted range 107 Value of "PositionIni" not within permitted range 108 Operating mode not permitted The virtual encoder velocity is large enough to exceed "ModuloValue"/2 in 500µs "VelocityMaxPos", "VelocityMaxNeg" or "Jerk- Max" is smaller than 0 Virtual encoder stops; Velocity = 0 Acceleration = 0 Virtual encoder stops; Velocity = 0 Acceleration = 0 Virtual encoder stops; Velocity = 0 Acceleration = 0 Virtual encoder stops; Velocity = 0 Acceleration = 0 Display only Virtual encoder stops; Velocity = 0 Acceleration = 0 Update firmware Check values for "VEncAccelerationMax" and "VEncDecelerationMax", correct if necessary Check values for "ModuloMin" and "ModuloMax": Reduce value for "ModuloMin" or increase value for "ModuloMax", if necessary Check value for "PositionSetpoint" Check value for "PositionIni" Check value for "VEncoderMode" Check values for "ModuloMin" and "ModuloMax". Check values for "VelocityMaxPos", "VelocityMaxNeg" and "JerkMax" 20 Virtual Encoder Technology Function MOVIAXIS MX Multi-Axis Servo Inverter

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