Reading a parameter value | Schneider Electric DS301 guide

IL•1F CANopen DS301

3 Basics

Reading data The client starts a read request by sending the index and subindex that point to the object or the object value whose value it wants to read.

The server confirms the request by sending the desired data. The SDO response contains the same index and subindex. The length of the re- sponse data is specified in the command code "ccd".

Client												Server
read request				0		1	2	3	4	5	6	7
				0		1	2	3	4	5	6	7
	COB-ID		ccd		Idx2 Idx1 Sidx					data
	ccd= 40h
	0	1		2		3	4	5	6	7		read response
	0	1		2		3	4	5	6	7
COB-ID	ccd	Idx	2	Idx	1	Sidx		data
			2		1
ccd= 43h								data
ccd= 47h								data
ccd= 4Bh							data
ccd= 4Fh							data

Figure 3.14 Reading a parameter value

Unused bytes in the data field are shown with a slash in the graphic. The content of these data fields is not defined.

ccd coding The table below shows the command code for transmitting a read value. It depends on the message type and the transmitted data length.

Message type	Data length used
	4	3	2	1 byte
	bytes	bytes	bytes

read request	40h	40h	40h	40h	Request read value
Read response	43h	47h	4Bh	4Fh	Return read value
Error response	80h	80h	80h	80h	Error

Table 3.6 Command code for transmitting a read value

0198441113586, V2.01, 11.2008

Fieldbus interface

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Image 29

Schneider Electric DS301 manual Reading a parameter value, Message type Data length used Byte Bytes

Contents

IL1F CANopen DS301 Important information Table of Contents Table of Contents IL1F CANopen DS301 Object directory Table of Contents IL1F CANopen DS301 Writing conventions and symbols Writing conventions and symbols IL1F CANopen DS301 CAN-Bus IntroductionAbout this manual Fieldbus devices networked via can bus Operating modes and functions in fieldbus mode Can users and manufacturers organization Documentation and literature references Introduction IL1F CANopen DS301 Before you begin safety information Before you begin safety information IL1F CANopen DS301 CANopen technology BasicsCANopen description language Communication layers Index hex Object groups Supported By the drive Objects IL1F CANopen DS301 Basics CANopen reference model CANopen profiles Index Subindex Object Meaning Communication profileObject dictionary Index range Object groups Supported Hex By the drive Communication objects Communication objects COB ID with function code and node address TPDO4 Master slave relationships Communication relationships Client-server relationship SDO data exchange Service data communicationOverview 11 SDO message, example SDO message Message type Data length used Bytes Reading and writing data Message type Data length used Byte Bytes 14 Reading a parameter value 15 Response with error message error response Process data communication 16 PDO data exchange PDO data exchange UINT32 18 Requesting a message with RTR = Dynamic and static PDO mapping Structure of RPDO4 Receive PDO RPDO4 master slave State machine drivectrl JOG Operating modes modeCtrl Transmit PDO TPDO4 product to master @ Warning 20 Structure of TPDO4 Structure of TPDO4 Bit Name Description Handshake with Mode Toggle Bit Master Slave Xend 22 Mode Toggle Handshake, short movement Basics IL1F CANopen DS301 23 Error message with the Emcy object Emergency service 25 Sync message Synchronization 27 Cyclic and acyclic transmission NMT services for device control Network management services Persistent data memory NMT service Transition MeaningInitialization Node/Life guarding NMT services for connection monitoringCommand Specifier NMT service Transition 31 Acknowledgement of the NMT slave 32 Node Guarding and Life Guarding with time intervals Installation Installation IL1F CANopen DS301 Commissioning the device Commissioning Commissioning the fieldbus network Starting fieldbus modeAddress and baud rate Error Error class Cause of error Troubleshooting Troubleshooting Selecting the CANopen master SyCon CANopen configuration softwareCreating a new network Setting the bus parameters Selecting and inserting nodes Overview Operation Operation IL1F CANopen DS301 Writing parameters Using SDO commandsTransmit data Receive data Index Sub Data Description Synchronous errorsReading a parameter Bit no Value Meaning Operating Name Power Description State StageChanging operating states with PDO4 Example Switching the power stage on and offTriggering a Quick Stop Come to a standstill System is to resume opera Resetting faults Examples for the operating modes with PDO4 Operating mode Profile Position absolute positioning Operating mode Profile Velocity Operating mode Profile Position relative positioning Master --- Slave Position setting Operating mode Homing Asynchronous errors Error signaling via PDO4 Positioning running xerr=0 Operation IL1F CANopen DS301 Fieldbus communication error diagnostics Diagnostics and troubleshooting Messages on the device status Error diagnostics via fieldbusMessage objects Error register CANopen error messagesError code table Bit Message Meaning Error code Meaning SDO error message Abort Object directory Specifications for the objectsObject code Meaning Coding Data type Value range Data length Objects, overview Index Subindex Designation Obj. code Data type Access Device type Error registerObjects of the product 1008h Bit coding, subindex 00hManufacturer device name 100Ch Index 100D h Object name Life time factor Object code Index 1018 h Object name Identity Object Object code Data type PDO Communication parameter Bit 30 RTR bit Bit assignment subindex 01hBit coding, subindex 02h Bit Acces Value Meaning 1603h Receive PDO4 mapping Value description BitMeaning 1803h Transmit PDO4 communication parameter Subindex 03 h, inhibit time TPDO4 Meaning IL1F CANopen DS301 Object directory PDO4 mapping 1603h Units and conversion tables Glossary Rotation TemperatureTorque Moment of inertia Terms and Abbreviations Default value Factory setting Power amplifier See power stage Can Index Index IL1F CANopen DS301 IL1F CANopen DS301 Index NMT IL1F CANopen DS301 Index 102 Fieldbus interface