Toshiba VF-A7 用户手册

 

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This section offers several configuration tips which can help to optimize the 
performance of communications with the ETH-100 and attached drives. 
 
1.  Configure Modbus programmable pointer registers to also be drive scan 

registers.  In the example configuration shown in Table 3, Modbus registers 
FC00 ~ FC07 are configured to point to the ASD scan registers.  In this case, a 
Modbus transaction beginning at address FC00 with a length of 8 can be 
processed extremely fast.  Of course, pointer registers can still be accessed if 
they are not configured as scan registers, but the transactions are slower, as they 
require transferring the request to the drive for processing. 

 

FA01 Read FC00 FA02 
FA00 Read FC01 FA01 

FD00 Read FC02 FD01 

FE01 Read FC03 FE02 

FC90 Read FC04 FC91 

FE03 Read FC05 FE04 
FE42 Read FC06 FE43 
FA22 Read FC07 FA23 

 
 
2.  Don’t leave a gap in the access sequence.  For optimal network response, 

make sure all of the pointer registers that you are going to access are also 
configured to be ASD scan registers.  The ETH-100 is most effective when all of 
the pointer registers that are going to be accessed are also ASD scan registers.  
In the example shown in Table 4, the high-speed processing of a Modbus register 
read starting at register 0xFC00 with a length of 8 will be delayed by the necessity 
to interact with the drive to obtain the values of drive registers 0xFC90 and 
0xFE03. 

FA01 Read FC00 FA02 
FA00 Read FC01 FA01 

FD00 Read FC02 FD01 

FE01 Read FC03 FE02 

  

FC04 

FC91 

  

FC05 

FE04 

FE42 Read FC06 FE43 
FA22 Read FC07 FA23