Bfm #200 To #6999: Data History - Mitsubishi FX3U-4AD User Manual

FX /FX /FX PLC User's Manual - Analog Control Edition
3G 3U 3UC
FX -4AD/FX -4AD (4-channel Analog Input)
3U 3UC

5.4.29 BFM #200 to #6999: Data history

Use this function to sample the A/D conversion data of each channel and to write the sampled data to the
buffer memories.
The 4AD can sample up to 1,700 points of A/D conversion data of each channel at the sampling cycle
specified in BFM #198, and can store the sampled data as history data in the buffer memories as shown in
the following table. Buffer memories are assigned to the 4 channels as shown in the following table, and data
is stored in the buffer memories in the order of the smallest BFM number to the largest BFM number.
Use BFM #199 to stop or reset the data history.
Number of data
samples
1st
2nd
3rd
1,700th
1. Caution regarding data history reading
If a large amount of history data is collectively read out to the PLC main unit using the FROM instruction, the
watchdog timer error may occur in the PLC main unit. Therefore, when programming, separate the history
data and then read it out using the FROM instruction. Set WDT (watchdog timer refresh) instruction between
the separated data.
B-50
BFM number
ch1 ch2
#200 #1900
#201 #1901
#202 #1902
#1899 #3599
Numeric data type: Decimal (K)
ch3 ch4
#3600 #5300
#3601 #4301
#3602 #4302
#5299 #6999
5 Buffer Memory (BFM)
5.4 Buffer Memory Details
Initial value: K0