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VACON® 1000 Fieldbus Options
Operating Guide
TPDO and RPDO apply to producer/consumer mode, and is often used in occasions with high requirement for speed. Upload SDO
and Download SDO apply to client/server mode, the mode can guarantee safety of data, and is often used in occasions with low
requirement for speed.
The data in Modbus output buffer of the gateway is the data being mapped to RPDO or Download SDO commands of CANopen
slave. Output mode of the gateway is "change of value". Until the Modbus output data is changed, the gateway transmits corre-
sponding commands (RPDO or Download SDO) to the CANopen network. For Modbus input data, the gateway receives data
through TPDO or Upload SDO commands configured in the configuration software SST-CM-CFG and saves the data to Modbus in-
put buffer.
The data exchange mode of Modbus and CANopen is shown in the following illustration. The data exchange buffer size is 1 kB,
input buffer is 512 bytes, and output buffer is 512 bytes.
Illustration 21: CANopen Master/Modbus Slave Data Exchange Mode
Modbus master reads 512 bytes input buffer data through function code 04, writes data into 512 bytes output buffer through func-
tion code 06/16, and reads 512 bytes output buffer data through function code 03.
•
Input buffer address range: 0x0000–0x01FF
•
Output buffer address range: 0x0000–0x01FF
Table 34: Input and Output Buffer Starting Address
Memory mapping address
Modbus slave PLC address
Modbus slave protocol address
Each Modbus command can read one continuous Modbus register.
When the "Control & Status" bit is "Enable" in configuration software, there are 2 bytes in the end of input and output buffer of the
gateway showing status of CANopen slaves and controlling status of CANopen slave. Modbus master can get the state (Operation,
Preoperation, Stop state) of CANopen through the gateway. Meanwhile, it can also change the operation state (Reset slave, Reset
Communication, and change the slave state) of the CANopen slave through the gateway by sending NMT control command.
Danfoss A/S © 2023.09
Gateway
Input buffer
(512 bytes)
Output buffer
(512 bytes)
Input Buffer
0000H–00FFH
30001–30256
0000H–00FFH
Output Buffer
0000H–00FFH
40001–40256
0000H–00FFH
AQ454734633756en-000101 / 172K1112 | 57
CANopen
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