Integrating SERCOS interface into CIP

Transcription

1 Presented by: Name Title Company Dr. Ludwig Leurs Manager Industrial Communication Technology Bosch Rexroth AG page 1

2 Overview Integrating SERCOS into CIP Industrial Network Domains SERCOS Basics Object model SERCOS Parameter structure Service Mapping Special Objects Identity Assembly page 2

3 Network Domains Easy Installation Control Network (Fieldbus) Switch Internet, Webaccess Connectivity Precision Installation Bus DeviceNet (flat cable) Control SERCOS Drives Drive Bus page 3

4 SERCOS Basics Optical fiber ring noisy environment, easy installation, no infrastructure components 2, 4, 8 and 16 Mbit/s Real Time Protocol designed for closed loop control exact synchronization of cycle time, command value valid time and feedback aquisition capture point cycle time from 62,5µs to 65ms Time Division Multiple Access (TDMA) protocol, high protocol efficiency limited bandwidth for acyclic data transfers page 4

5 MST t1.1 AT1 t1.2 SERCOS Telegram Sequence MDT AT2 ATm ATM MST t1.m t1.m t2 tscyc t1 t2 tscyc AT transmission starting time MDT transmission starting time SERCOS cycle time page 5

6 Master Data Telegram (MDT) Example BOF ADR (255) Data record 1 Data record k Data record K FCS EOF Control Master Service Info Data Record k for drive xx Operation data for drive xx Fixed part of data record Configurable part of data record Operation data IDN ***** Operation data IDN ***** Operation data IDN ***** Operation data IDN ***** page 6

7 CIP Object Model Device specific Class Instance, Attribute Open object class range Vendor specific object class range Vendor specific instance and attribute extensions to open object classes Object Models SERCOS Object Model Device specific Ident number (IDN), element number Standard parameter (IDN) range Product specific parameter range Not possible page 7

8 SERCOS Device Parameters Each device has ist own parameter set parameters are defined from the device view representation of SERCOS IDNs S = Bit 0-11 Ident number Parameter number Parameter set (0-7, gearbox) 0 = Standard parameter (S) 1 = Product specific param. (P) page 8

9 SERCOS Parameter Examples (1) Communication parameters S Control unit cycle time Real time control parameters S Feedback acquisition capture point motion control parameters S Position feedback value 1 (motor feedback) S Velocity feedback value 1 (motor feedback) S Torque feedback value page 9

10 SERCOS Parameter Examples (2) Application parameters S Position switch point 1 S Standstill window (velocity threshold) S Probe value 1 positive edge page 10

11 SERCOS Parameter Structure A SERCOS parameter is a structure of 7 elements 1. Ident number 2. Name 3. Attribute 4. Unit 5. Minimum value 6. Maximum value 7. Operational data used as multiplexor in service channel (acyclic) ASCII string for parameter name coded data type, scaling factor, access rights, display presentation ASCII string for physical unit lower limit upper limit actual value of parameter page 11

12 Object access Supported Services CIP service SERCOS service Get_Attribute_Single Read parameter element Set_Attribute_Single Write parameter element Reset - Conversion of services needs a gateway very simple, if 1:1 object mapping done in the motion control, no extra hardware cost page 12

13 CIP to SERCOS Service conversion example Read SERCOS parameter value S Motor temperature value The actual value of the motor temperature is 50,5 C The telegram sequence is: CIP Explicit Request ::= GetAttributeSingle.req (SercosObjectClass, instance = 383, attribute_id = 7) Sercos Request ::= ReadParameter (Ident_number = 383, element_number = 7) Sercos Response = 505 CIP Explicit Response ::= GetAttributeSingle.res, 505 Error codes will have to be mapped missing parameters Object does not exist missing elements Attribute not supported prohibites write access Attribute not settable page 13

14 Special Objects Identity Mapping of attributes needs extra efforts VendorID new SERCOS parameter tbd by SERCOS TWG Device Type S Sercos Device Type Product Code not applicable, tbd by SIG Revision tbd by SIG Status derived from SERCOS drive status Serial number new SERCOS parameter, Product name S Sercos Controller type page 14

15 Special Objects Assembly Contains information about real time data (implicit messages) Attributes: number of members in List ::= number of members in S for input assemblies or S for output assemblies member list ::= S converted to list of SercosObject instances (for inputs) Data := Drive Telegram (for inputs) This information could also be accessed through Instance 16 of the proposed CIP Sercos Object Class (S ) page 15

16 Special Objects Object Directory & Message Router SERCOS parameter S lists all available IDNs of its device. S represents a list of available instances of the proposed Sercos Object Class. S is mantadory for SERCOS devices A full device description can be generated only using the Sercos Object Class The Message Router Object can optionally contain a list of supported classes it s safe and simple to use the S list of device parameters page 16

17 CIP Sercos Object Proposed mapping CIP Sercos Object Class in open class range Instances numbers are SERCOS Ident numbers AttributIDs are SERCOS element numbers page 17

18 Conclusions Careful timing design makes SERCOS best choice for coordinated motion systems CIP and its routing capabilities offer the best connectivity CIP and SERCOS are object oriented device models both are international standards combining both via parameter mapping gives full strength page 18

19 Facility Management Ethernet Integration Scenario WAN Engineering Remote Diagnosis ControlNet page 19