Mitsubishi Electric MELSEC Q Series User Manual page 174

(1) Setting method
For this setting, use the following functions in Setting/monitoring tools for the C Controller module.
•
Project view  "Parameter"  "CCPU Parameter"  <<Data refresh settings>>
The number of points available for data refresh settings is up to 48K words.
(2) Data refresh time
The following indicates formulas to obtain time required for data refreshing.
Data refresh time D (ms)
= ((CCPU device access time)  ((Total X/Y points / 16  1 word access time (T
+
(CPU shared memory / buffer memory access time)  (Total points of G  1 word access time (T
+
(Number of settings  K
*5
) / 1000
= 2 s
*1 : T
1
= 0.2 s
*2 : T
2
= 0.01 s
*3 : T
3
K = 16 s
*4 :
*5 : Odd numbers should be rounded up.
In any of the following conditions, data refresh delay may occur.
• The user program is accessing to the device
• An interrupt event from an interrupt module or an intelligent function module occurs
• The system is communicating with peripheral(s)
(3) How to access the data refresh memory
The data refresh memory can be accessed by using the following C Controller module dedicated function from
the user program.
Function name
CCPU_WriteDataRefreshMemory
CCPU_ReadDataRefreshMemory
172
+
(Total points of M/B/SM / 16  1 word access time (T
+
(Total points of D/W/SD  1 word access time (T
*4
)
Writes data to the data refresh memory of the C controller module.
Reads data from the data refresh memory of the C controller module.
*1
))
1
*2
))
2
*2
) )
2
*3
))
3
For "-LS", consult with the
partner (operating system vendor).
Function