Mitsubishi Electric MELSEC iQ-F FX5 User Manual page 147

■Buffer memory address
The following shows the buffer memory address of this area.
Buffer memory name
CH Difference conversion standard value
CH Difference conversion standard value (in
FX3 allocation mode function)
Even if 'CH1 Difference conversion state flag' (Un\G408) is turned from Converting difference (1) to Not
converted (0), 'CH1 Difference conversion reference value' (Un\G432) is not cleared.
CH1 Head pointer
The buffer memory address of the oldest data in CH1 Logging data (Un\G10000 to Un\G19999) can be checked with this
buffer memory area.
The offset value counted from the start address of CH1 Logging data (Un\G10000 to Un\G19999) is stored.
■Buffer memory address
The following shows the buffer memory address of this area.
Buffer memory name
CH Head pointer
CH Head pointer (in FX3 allocation mode
function)
Ex.
When the value of 'CH2 Head pointer' (Un\G634) is 8550
Head pointer: 8550
(Offset value from Un\G20000)
■Default value
The default value is 0 for all channels.
• The value in 'CH1 Head pointer' (Un\G434) is fixed to 0 since the oldest data is stored in the start address of
CH1 Logging data (Un\G10000 to Un\G19999) while the data of the first 10000 points is being logged from
beginning of the logging. On and after the 10001st data, 'CH1 Head pointer' (Un\G434) increases one by
one each time data is stored.
• When 'CH1 Logging hold request' (Un\G471) is turned onoff, 'CH1 Head pointer' (Un\G434) is cleared to
0.
CH1 CH2
432 632
1371 1372
CH1
434
9031
CH2 Logging data
Un\G20000
The latest data
Un\G28549
The oldest data
Un\G28550
28550 = 20000 + 8550
Un\G29999
CH3
832
1373
CH2 CH3
634 834
9032 9033
Appendix 4 Buffer Memory Areas
CH4
1032
1374
CH4
1034
9034
A
APPX
145