DEVICE CANOPEN
1. Introduction
The CANOPEN device is an object that can be used for configuring, monitoring and managing a CANOpen network. CANopen is a communication protocol based on CAN bus. For every reference to CiA documents please refer to Protocol: the international organization that develops and promotes the protocols based on CAN bus (http://www.can-cia.org/cia).
1.1 Device declaration
In the configuration section INTDEVICE unit must be declared so that you have the hardware necessary to use the CANOPEN device. In the INTDEVICE section of the unit of configuration must be added the following definition:
;--------------------------------- ; Device declaration ;--------------------------------- INTDEVICE ... <device_name> CANOPEN TCamp Speed Port
Where:
| <device_name> | the name given to the device |
| CANOPEN | keyword that identifies the device analog positioner |
| TCamp | sample time device (1÷255 ms) |
| Speed | indicates the value in Kbps of speed. Accepted values are 1000, 500, 250 and 125. On some hardware, you can also set the value 0. In this case the CANbus speed is set with the dip-switches. The value of the selected speed will be visible in the parameter speed |
| Port | indicates the CAN unit to which the device is to be referred. If your hardware is slated to only one port CAN use the value 0 |
 | Attention: It is necessary that each definition are present on the same line. |
|---|
1.2 Operation
The main features of the CANOPEN device are:
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CANbus network monitoring: some switches allow you to control the errors of the CAN network, to estimate traffic bus, check some typical CANbus device States
-
receiving and decoding of emergency messages typical of the CANOpen protocol
-
managing QDO (Qem Data Object) they are objects that do not have a direct relationship with the Protocol, but enhance ensure the possibility of CANOpen communication library configuration. For example the QDO are used to define the refresh rate of the analog inputs, to define the Division factor of position read from a drive, etc.
Here is a list of currently available QDO:
| index | Name | Default value | Access | Range of values | Short description |
|---|---|---|---|---|---|
| 1 | aiperiod | 100 | RW | 0÷32767 | Update time analog and count inputs expressed in ms |
| 2 | setdrivemode | - | RW | 0÷255 | Sets the drive to work with indicated mode and DS402 specification |
| 3 | targetpos | - | W | - | Sets the source location for the drive. Your writing should be done with the drive not operational. This parameter is automatically set with the QDO setdrivemode. |
| 4 | divfactor | 2 | RW | 0÷4 | Sets the divider for positions. The value is the divisor expressed as an exponent of 2. (example: 2 means 22 = 4) |
| 5 | Slave Link Status | - | R | Indicates the linkup of the slaves. The State of bit 0 corresponds to the status of links of the slave with address 1 | |
| 6 | Slave Link Up | - | W | Adds to the CANOpen network one slave in link down. Bit 0 corresponds to the slave with address 1 | |
| 7 | Sync Mode | RW | 0÷1 | Sets the message SYNC mode (0 for DS401, 1 for DS402 in interpolation mode) | |
| 8 | Guard Time | RW | - | Sets the Guard Time of the NodeGuarding protocol | |
| 9 | SDO timeout | RW | - | Sets the timeout value of the SDO messages |
1.2.1 "Slave Link Status" use example
Example of a unit created for Qview 6 with local declaration and CANOPEN device declared as REFERENCE.
CONST
READ_LINK_STATUS__TIME 1000
GLOBAL
ErrorCode B OUT
SlavesLinkDown L OUT ; link down state (bit0=slaveID1, bit1=slaveID2, ecc)
TIMER
tmLinkStatus
INTDEVICE
CanOpen CANOPEN REFERENCE
BEGIN
MAIN:
IF tmLinkStatus
tmLinkStatus = READ_LINK_STATUS__TIME
CanOpen.index = 5
CanOpen.READQDO
WAIT CanOpen.st_send
IF NOT CanOpen.qdoerr
SlavesLinkDown = CanOpen.data
ErrorCode = 0
ELSE
ErrorCode = 1
ENDIF
ENDIF
WAIT 1
JUMP MAIN
END
1.3 Parameters table
| Name | Dimension | Default value | Access type | Unit of measure | Valid range | Write conditions | Description |
|---|---|---|---|---|---|---|---|
| speed | Word | - | R | Kbps | 1000, 500, 250, 125 o 0 | - | Transmission speed Shows the relevant setting on the device for the transmission speed. |
| maxrxerr | Word | 0 | RW | - | - | - | Maximum number of receive errors Shows the maximum number of receive errors. |
| maxtxerr | Word | 0 | RW | - | - | - | Maximum number of errors in transmission Shows the maximum number of errors in transmission. |
| busload | Word | 0 | R | Percentage | 0÷100 | - | Bus load Indicates the network traffic load as a percentage, the value is updated every 500 ms. |
| maxtraffic | Word | 0 | RW | Percentage | 0÷100 | - | Maximum load detected in bus Shows the maximum percentage of traffic detected on the bus from the last reset of this parameter. |
| errflags | Word | 0 | RW | - | 0÷32768 | - | Error flag indicator The value is the result of the conversion to decimal values of some bit flags, at every mistake every flag is placed at 1, to clear them you can set the parameter to 0. All of these error messages are sent from the chip that manages communication CAN. bit0 overrun error bit1 rx buffer full error bit2 idle character detect bit3 bus-off state bit4 transmitter error passive bit5 receiver error passive bit6 transmitter warning bit7 receiver warning bit8 acknowledge error bit9 CRC error bit10 form error bit11 stuff bit error bit12 bit 0 error bit13 bit 1 error bit14 received message queue full bit15 transmit message queue full bit16 receiver busy |
| unit | Byte | 0 | RW | - | - | - | CANOpen unit's identification number Identifies the number of CANOpen drive that will use the READSDO and WRITESDO commands. |
| index | Long | 0 | RW | - | 0÷65535 | - | Index of Dictionary objects Identifies the index of the Dictionary objects. |
| subindex | Word | 0 | RW | - | 0÷255 | - | Sub-Index of Dictionary objects Identifies the sub-index of the Dictionary objects in the case that the object is of complex type. |
| length | Word | 0 | RW | bytes | - | - | Dimension SDO Indicates the size in bytes of the SDO read or written. |
| data | Long | 0 | RW | - | - | - | SDO or QDO value Indicates the QDO or SDO value to be read or written. |
| string1÷16 | Byte | 0 | RW | - | - | - | SDO value Indicates the SDO value read or written in the case that the data is of type VISIBLE_STRING or OCTET_STRING. |
| sdoerr | Byte | 0 | R | - | - | - | Error while the SDO processing Indicates an error made while of the SDO reading or writing. The value must be read after st_send is placed to 1. The error codes are: 6 Invalid unit 10 invalid group number 11 invalid SDO 12 communication error 13 length invalid SDO 17 wrong unit 28 invalid message length 29 transmission error 34 not valid object length |
| qdoerr | Byte | 0 | R | - | - | - | Error while QDO processing Indicates an error made while of the QDO reading or writing. The value must be read after st_send is placed to 1. The error codes are: 1 object not available 2 error in the QDO running 3 value of the QDO used beyond the limits |
| sdoabort | Word | 0 | R | - | - | - | SDO abort code CAN protocol error messages. (Not yet implemented) |
| emcyunit | Byte | 0 | R | - | - | - | Emergency unit Indicates the number of units located in emergency. |
| emcycode | Word | 0 | R | - | - | - | Emergency message code Indicates the emergency message code. |
| emcyreg | Byte | 0 | R | - | - | - | Error log emergencies Emergency message error log. |
| emcyman1÷5 | Byte | 0 | R | - | - | - | Error constructor These parameters allow you to read the value of the “manufacturer specific error register” field of the emergency message. |
| errcode | Byte | 0 | R | - | 0÷100 | st_error=1 | Error identification code Indicates the type of failure intervened in the system. When st_error = 1 is present on the errcode variable the type of failure intervened and in the errvalu variable and e an indication on the cause of the error. |
| errvalue | Byte | 0 | R | - | 0÷100 | - | Identifying code of the cause of the error Indicates the cause of the error in the system. The code is valid only if st_error = 1. |
| wrncode | Byte | 0 | R | - | 0÷100 | - | Identification code warning Indicates the type of warning in the system. The st_warning state indicates a minor event that guarantees the operation of the device. When st_warning is equal to 1, are present on the wrncode variable the type of warning intervened (see the table) and in the wrnvalue variable an indication as to the cause of the warning. |
| wrnvalue | Byte | 0 | R | - | 0÷100 | - | Identification code of the cause of the warning Indicates the cause of the warning in the system. 1: attempt to write access on a parameter where the conditions for writing were not met, 2: attempt to execute a command when the conditions weren't met. |
1.4 Status table
| Noae | Short description | Descrizption |
|---|---|---|
| st_send | 1 | SDO or QDO commands executed When the State takes the value 1 indicates that the SDO command (READSDO or WRITESDO) or QDO (READQDO or WRITEQDO) it's executed. |
| st_emcy | 0 | State of emergency The device has received an emergency message when the State is worth 1. |
| st_error | 0 | Error presence Indicates the error status of the device, to recognize the type of error you must refer to the errcode and errvalue variables: 0: error not present, 1: error present |
| st_warning | 0 | The presence of a warning Indicates the device warning status, to recognize the type of warning you must refer to the wrncode eand wrnalue variables: 0: warning not present, 1: warning present |
1.5 Commands table
| Name | Condition | Description |
|---|---|---|
| READSDO | st_send=1 | Reading an SDO Read command. The following parameters must be set: unit, index, subindex. Upon activation of the st_send state you can verify the parameters to check for an error. If the operation went successful then in data or string1÷16 parameters, you will find the value of the object and in the length parameter you find the size of the data. |
| WRITESDO | st_send=1 | Writing an SDO Command of writing an SDO. The following parameters must be set: unit, index, subindex, length and data. Upon activation of the st_send state you can verify the parameters to check for an error. |
| READQDO | st_send=1 | Reading an SDO Read command a QDO. The following parameters must be set: unit, index, subindex. Upon activation of the st_send state you can verify the qdoerr parameter to check for an error. |
| WRITEQDO | st_send=1 | Writing an SDO A write command QDO. The following parameters must be set: unit, index, subindex, length and data. Upon activation of the st_send state you can check the qdoerr parameter to check for an error. |
| READEMCY | st_emcy=1 | Reading an emergency message It commands an emergency message reading. When the st_emcy state becomes active means that the device has received an error message, and you can read it with this command. The emcyunit, emcycode, emcyreg and emcyman1÷5 parameters represent the data in your message. |
| RSERR | st_error=1 | Reset error state Reset the st_error state. |
| RSWRN | st_warning=1 | Reset warning state Reset the st_warning state. |