Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual CONTENTS 1. CAN bus & CANopen protocol ...... 1 2.2 Parameters saving ........15 1.1 CAN bus ............1 3. Diagnosis and useful information ....15 1.2 CAN bus Characteristics ......1 3.1 Error diagnosis field bus communication .
Association) through which devices, actuators and sensors from different manufacturers can communicate with each other. Elap encoder complies with standards CiA DS 301 “Application Layer and Communication Profile” and DS 406 “Device Profile for Encoders.” 1.2 CAN bus Characteristics Data rate of 1 MBaud with network expansion up to 40 ...
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual CANopen permits: • Simplified access to all device and communication parameters • Synchronization of several devices • Automatic configuration of the network • Cyclical and event-controlled process data communication CANopen comprises four communication objects (COB) with different characteristics: •...
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual Other messages: Function code COB ID Emergency 80H + Node ID PDO1 (tx) 180H + Node PDO2 (tx) 280H + Node SDO (tx) 580H + Node SDO (rx) 600H + Node Heartbeat 700H + Node LSS (tx)
Page 6
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual The command byte defines whether data is read or set, and how many data bytes are involved. SDO Command Description Data length Download request Max 4 byte Transmits parameter to encoder Download request 4 byte Download request...
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual Writing of a value by the master into the encoder (Position setting can be performed with preset, object 6003H, at 300H). COB ID Command ObjectL ObjectH Sub-ind Data 0 Data 1 Data 2 Data 3 600H+Node...
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual Byte 1 and 2 contain the error code. Code Meaning 0000H Error reset/ no error 1000H Generic error 6010H Software reset (watchdog) 7320H Position error 8110H CAN communication error (Overrun) 8120H CAN communication error (Transmission / Reception) 8140H...
Page 9
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual NMT states Initialization Following initialization, the encoder logs on to the CAN bus with a BootUp message. The encoder then goes automatically to the pre-operational mode status. The COB ID of the BootUp message is made up of 700H and the node ID. COB ID Byte 1 700H + Node...
Encoder MEM40B – MEM41B with CANopen protocol – Instruction Manual Communication reset The encoder re-initializes the communication and switches to the pre-operational mode status. COB ID Command Node 00H, …, 7FH Heartbeat Protocol The encoder (Heartbeat producer) transmits the Heartbeat message cyclically with the frequency defined in the object 1017H.
Page 11
Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 7E4H Reserved Vendor ID ELAP: 000002B4H Product code: Encoder inside code (see label) Revision number: Current encoder revision (see label) Setting the node ID After setting the encoder in the configuration mode, it is possible to modify the node ID.
Page 13
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion Requesting the product code With this message the master requests the selected slave (that is in the configuration state) the product code. The slave response with the requested data in bytes 1 to 4 follows. COB ID Command Byte 1...
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion 2. Encoder communication profile 2.1 Overview of encoder objects According to CiA (CAN in Automation), objects are subdivided into three groups: • Standard objects (see DS 301, Application Layer and Communication Profile) 1000H, 1001H, 1018H ...
Page 15
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion Object Name Type Attr Default Info 1018H Identity Object Biggest Subindex Vendor ID 000002B4H Manufacturer Id (by CiA) 0AH multiturn, 0BH single turn Product code Revision No. Current revision 1029H Error behavior Object present from 1.10 version...
Page 16
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion Object Name Type Attr Default Info 0000H Bit0 rotation direction 6000H Operational parameters clockwise rotation anti-clockwise rotation Bit2 scaling function disabled enabled Resolution – single turn 6001H 00002000H 13 bit resolution; accepted values: 01H to 2000H.
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion 2.2 Parameters saving The objects below are saved via object 1010H. In order to prevent unintentional saving, the message "save" must be written in subindex 1. The saving operation is necessary to store modifications performed in the objects below.
3. On next initialization, the sensor logs on with the new node ID. Modifying the baud rate: 1. The baud rate can be set in Elap specific object 2100H 2. The new baud rate is saved into RAM buffer. 3. On next initialization the encoder logs on with the new baud rate.
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion 4. Applications 4.1 Reading and setting objects In order to overwrite an object (SDO) or to read it, two telegrams always have to be transmitted: one request from the master and one confirmation by the slave. Example: setting an object Setting the Heartbeat time (object 1017H, default = 2000 ms) 1500 ms (= 05DCH).
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion Changing the node ID (node no.) The node ID can be changed in object 2101H between 1 and 127. On the next initialization, the encoder logs on with the new node ID. Example: node no.
Page 21
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion Changing the sense of rotation and scaling The sense of rotation can be set to CW (clockwise) or CCW (counterclockwise). In addition, the scaling can be switched on or off in the same object (6000H). With the scaling switched on, the set resolutions are used. If the scaling is switched off, the encoder works with the maximum resolution settings (objects 6501H and 6502H).
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion 4.3 Operation NMT statuses Once the encoder has been initialized, it is then in the Pre-operational mode. In this mode, SDO can be read and written. In order to start PDO communication, you must transmit an NMT start. The encoder is then in the Operational mode.
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion 5. Hardware configuration The encoder rear cap must be removed to gain access to two rotary switches, one 4-pin DIP switch and one 8-pin tap connector (Picture 5.1). The 8-pin tap connector can be disconnected and is supplied inserted in the corresponding plug connector.
Encoder MEM-Bus con protocollo CANopen – Manuale di istruzion If the connected encoder is the last device in the bus line, the bus must be terminated with a resistor. The resistor can be connected by the contact 4 of the encoder DIP switch (see TABLE 5.2). The default set of the DIP swicht contact4 is: OFF.
Need help?
Do you have a question about the MEM40 Bus and is the answer not in the manual?
Questions and answers