CANOpen Transducer Digital Communication

CANOpen Transducer Digital Communication
CANOpen Transducer
Digital Communication
User’s Manual
Firmware Version 231706B
Stellar Technology Incorporated
P/N 234310 Rev. B
CANOpen Transducer Digital Communication
P/N 234310 Rev. B
Contents
CANOPEN COMMUNICATION PARAMETERS ...................................................... 3 PDOS .................................................................................................................................. 4 SDOS .................................................................................................................................. 5 MANDATORY OBJECTS: ................................................................................................... 7 OPTIONAL OBJECTS: ........................................................................................................ 7 MANUFACTURER OBJECTS: .............................................................................................. 7 LAYER SETTING SERVICES (LSS) ............................................................................ 9 SWITCH GLOBAL:............................................................................................................. 9 SWITCH SELECTIVE: ....................................................................................................... 10 SAVING PARAMETERS: ................................................................................................... 11 Page 2 of 12
CANOpen Transducer Digital Communication
P/N 234310 Rev. B
CANOpen communication parameters
Baud rate: 125 (default), 250, 500 kBit/sec
Node ID: 0x01 (default)
Transmission type: 0xFE – asynchronous PDO, transmitted cyclically with the
event time, measured in milliseconds
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
PDOs
Single TPDO with 0x180 + Node_ID + DATA
The DATA type REAL32 is represented as bit sequence of length 32. The
encoding of values follows IEEE754.
It is transmitted in the following order:
Octet number
REAL32
1
0x00
B7..B0
2
0x00
B15..B8
3
0xC8
B23..B16
4
0x40
B31..B24
Setting PDO Event Time to 0 will stop PDO transmission.
The PDO will be transmitted on SYNC object when in Operational Mode.
Setting Heartbeat Time to 0 will stop Heartbeat transmission.
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
SDOs
The message for the Initiate SDO Download service, with which a write access to
an object dictionary entry of a CANopen node occurs at the same time, is
structured as follows:
Command
OD Index
OD sub-index
Data ( max. 4 bytes)
The SDO server responds with protocol byte 0x60:
0x60
OD Index
OD sub-index
Empty (4 bytes)
An SDO download to the OD entry 0x1017, with which the heartbeat interval of a
heartbeat producer is to be set to 4 seconds (in ms as an UNSIGNED16 value,
i.e. 0x0FA0), therefore appears as follows:
0x2B
0x17 0x10
0x00
0xA0 0x0F 0x00 0x00
The node (SDO server) then acknowledges successful completion with the
message:
0x60
0x17 0x10
0x00
0x00 0x00 0x00 0x00
An SDO download to the OD entry 0x2004, sub-index 0x01, with which the zero
offset of 1.23 PSI is set, appears as follows:
0x2B
0x04 0x20
0x01
0xA4 0x70 0x9D 0x3F
The node (SDO server) then acknowledges successful completion with the
message:
0x60
0x04 0x20
0x01
0x00 0x00 0x00 0x00
With the Initiate SDO Upload service, with which an object dictionary entry of a
CANopen node is read out, the same division of the data field is valid, only here
request and response telegrams are reversed to a certain extent. Here is the
command byte of the client request 0x40:
Command 0x40
OD Index
OD sub-index
Empty (4 bytes)
OD sub-index
Data (4 bytes)
The SDO server responds with:
Command 0x40
OD Index
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
An SDO upload to the OD entry 0x2004, sub-index 0x01, with which the zero
appears as follows:
0x40
0x04 0x20
0x01
0x00 0x00 0x00 0x00
The node (SDO server) then replies with offset value. In this example offset is
equal to 1.23 PSI:
0x60
0x04 0x20
0x01
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0xA4 0x70 0x9D 0x3F
CANOpen Transducer Digital Communication
Mandatory Objects:
0x1000 – Device Type
0x1001 – Error Register
0x1018 – Identity Object
Sub 1: Vendor ID
Sub 2: Product Code
Sub 3: Revision Number
Sub 4: Serial Number
(0x00040194)
(0x00000250)
(0x00000000)
(0x00000000)
Optional Objects:
0x1003 Pre-Defined Error Field
Sub 0: Number of Errors
Sub 1: Standard Error Field
0x1005 COB ID SYNC
0x1008 Device Name
0x1009 HW Version
(0001)
0x1010 Store Parameters
0x1011 Restore Parameters
0x100A SW Version
(0001)
0x1014 COB ID Emergency
0x1015 COB ID Emergency Inhibit
0x1017 Producer Heartbeat time (1000 = 1 sec)
0x1800 Transmit PDO Communication Parameter
Sub 1: COB ID
(0x180)
Sub 2: Transmission Type (0xFE)
Sub 3: Inhibit Time
(100)
Sub 5: Event Timer
(1000000 = 100 sec)
Manufacturer Objects:
0x2000 Calibration Data
Sub 1: AmbTemp
Sub 2: AmbInc0
Sub 3: AmbInc20
Sub 4: AmbInc40
Sub 5: AmbInc60
Sub 6: AmbInc80
Sub 7: AmbInc100
Sub 8: AmbDec80
Sub 9: AmbDec60
Sub 10: AmbDec40
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P/N 234310 Rev. B
CANOpen Transducer Digital Communication
Sub 11: AmbDec20
Sub 12: AmbDec0
Sub 13: ColdTemp
Sub 14: Cold0
Sub 15: Cold100
Sub 16: HotTemp
Sub 17: Hot0
Sub 18: Hot100
Sub 19: IdealHI
Sub 20: IdealLow
0x2003 NULL Process Value (Pressure)
0x2004 Zero Offset for Process Value
Sub 1: Pressure
0x2005 Span (in %)
Sub 1: Pressure
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P/N 234310 Rev. B
CANOpen Transducer Digital Communication
P/N 234310 Rev. B
Layer Setting Services (LSS)
Switch Global:
The CANopen specification DS-306: Layer Setting Services (LSS) describes how
the baud rate and the Node_IDs can be set via the bus with the aid of a simple
protocol.
To make contact with a device to be configured, the "Switch Mode Global"
command is transmitted:
0x04
0x01
0x00 0x00 0x00 0x00
This command sets the device to LSS configuration mode. This service is the
only unacknowledged LSS service, to which the device will not respond. The
system integrator can therefore only find out with the following command whether
the device has reacted.
Node_ID is requested via the "Inquire Node-ID" service:
0x5E
0x00
0x00 0x00 0x00 0x00
If successful, the device responds with:
0x5E
Node_ID
0x00 0x00 0x00 0x00
If there is no response, then either the device does not support the LSS service
or the baud rate is not correct. If, namely, the baud rate when supplied is not
known, the above-mentioned communication sequence must be tested with all
permissible CANopen baud rates until the device is found.
The "Configure Node-ID" service is used to configure the new Node_ID:
0x11
Node_ID
0x00 0x00 0x00 0x00
The error code is included in the device response:
0x11
Error Code
Error Extension reserved
Error code 0 means success; error code 1 means inadmissible Node_ID; the
other error codes are reserved. The error extension contains vendor-specific
information, but is only valid for error code 0xFF.
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
The baud rate is configured with the "Configure Bit Timing Parameters" service:
0x13
Bit timing table
Table entry
0x00 0x00 0x00 0x00
The standardized CANopen baud rates are listed in the following table:
Baudrate table 0x00
Table Baudrate
index
0
1000 kBit/s
1
800 kBit/s
2
500 kBit/s
3
250 kBit/s
4
125 kBit/s
5
reserved
6
50 kBit/s
7
20 kBit/s
8
10 kBit/s
The current implementation of CANOpen by STI supports only 500, 250 and 125
kBit/s baud rates.
Now that the Node_ID and baud rate are configured, these settings should be
saved with the "Store Configuration" service:
0x17
reserved
The device acknowledges:
0x17
Error
Code
Error
Extension
reserved
Error code 0 means success; error code 1 means that the device does not
support saving; error code 2 means that there is a problem with access to the
storage medium; the other error codes are reserved. The error extension
contains vendor-specific information, but is only valid for error code 0xFF.
Finally, the device is switched back from configuration mode to normal mode via
"Switch Mode Global":
0x04
0x00
0x00 0x00 0x00 0x00
Switch Selective:
An LSS Slave is identified by an LSS Address. An LSS Address consists of a
Vendor ID, a Priduct Code, a Revision Number and a Serial Number. The Vendor
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
ID and Product Code are numerical numbers. The Revision Number contains the
major and minor revision as numerical number. The Serial Number is coded as a
numerical number too. They adhere to the following syntax:
<LSS-ADDRESS> = <Vendor ID><Product Code><Revision Number><Serial
Number>
Vendor ID
= 0x00000250 (STI)
Product Code
= 0x00000000
Revision Number = 0x00000000
Serial Number
= UNSIGNEDINT32
A Vendor ID is assigned to module suppliers by CiA. A Product Code, Revision
Number and a Serial Number are assigned by the module supplier. For LSS
Addresses the following conditions must be met:
- The LSS Address is identical to the CANopen identity object.
- The LSS Address of a LSS Slave can be inquired.
- There exists no other LSS Slave in the world with the same LSS Address
To select a device using LSS Switch Selective the following sequence of
commands must be executed:
0x40
Vendor_ID
0x00 0x00 0x00
0x41
Product Code
0x00 0x00 0x00
0x42
Revision Number
0x00 0x00 0x00
0x43
Serial Number
0x00 0x00 0x00
If there is matching device on the network, it will go into Configuration mode and
reply with:
0x44
0x00 0x00 0x00 0x00
0x00 0x00 0x00 0x00
Below you will find an example of CAN frames to be send for an STI CANOpen
transducer with SN 123456.
0x40
0x50 0x02 0x00 0x00
0x00 0x00 0x00
0x41
0x00 0x00 0x00 0x00
0x00 0x00 0x00
0x42
0x00 0x00 0x00 0x00
0x00 0x00 0x00
0x43
0x40 0xE2 0x01 0x00
0x00 0x00 0x00
Saving Parameters:
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CANOpen Transducer Digital Communication
P/N 234310 Rev. B
In order for all the changes to be stored in non-volatile memory, the word “save”
must be written to the OD entry 0x1010, sub-index 0x01 – Store parameters.
0x2B
0x10 0x10
0x01
0x65 0x76 0x61 0x73
The node (SDO server) then acknowledges successful completion with the
message:
0x60
0x10 0x10
0x01
0x00 0x00 0x00 0x00
After being switched physically off and on again, the device now works with the
new settings.
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