Buffer Memory Access - Mitsubishi Electric MELSEC Q Series User Manual

13.2.3

Buffer memory access

Buffer memory access is a method to access network module buffer memory from the user program.
C Controller module
User program
(1) Function to use
The dedicated function is used from the user program to access buffer memory.
Functions used for access by buffer memory are indicated below.
(a) Bus interface functions
Function name
QBF_ToBuf
QBF_FromBuf
QBF_RefreshLinkDevice
(b) MELSEC data link functions
Function name
mdSendEx
mdRandWEx
mdReceiveEx
mdRandREx
● Proper use of dedicated function libraries
To access to module(s) in the same C Controller module, use of bus interface functions better improves the user program
processing performance.
CHAPTER 13 FUNCTIONS ACCESSED VIA A NETWORK MODULE
Network module
Link
device
Buffer memory access
Buffer memory
Writes data directly into network module buffer memory.
Reads data from the network module buffer memory.
Requests refresh to read data from /write data to the CC-Link module buffer memory and
link device(s). (Used when the manual refresh is selected)
Writes data directly into network module buffer memory.
Reads data from the network module buffer memory.
Q24DHC-LS
Q24DHC-V Q24DHC-VG
Network module
Link
Link
device
scan
Function
Function
Q26DHC-LS
Q12DC-V
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