244 Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Chapter 12          Using microSD Cards
Data Log Performance
UDINT(DWORD) Unsigned 32-bit integer value 0, 4294967295
ULINT(LWORD) Unsigned 64-bit integer value 0, 18446744073709551615
REAL 32-bit floating point value -3.40282347E+38, +3.40282347E+38
LREAL 64-bit floating point value -1.7976931348623157E+308, +1.7976931348623157E+308
STRING
(2)
character string 
(1 byte per character)
'"Rotation Speed"
DATE
(1)
Unsigned 32-bit 
integer value
1234567 
(Date variables are stored as 32-bit words, a positive number 
of seconds beginning at 1970-01-01 at midnight GMT.)
TIME
(1)
Unsigned 32-bit 
integer value
1234567 
(Time variables are stored as 32-bit words, positive number of 
milliseconds).
(1) BOOL, DATE, TIME data variables are presented in decimal digital format in the microSD Card. You have the option to convert 
this format to a more friendly format. For example, use ANY_TO_STRING function block to convert BOOL data type (0, 1) to 
FALSE or TRUE. You can similarly do the same for DATE and TIME data types.
DATE data type is presented in differential decimal digital value between system baseline time (1970/01/01,00:00:00) and 
current date value. Unit is millisecond. 
Time should be absolute time value. Unit is second. 
(2) String data variables are enclosed in double quotation marks in the data log file. 
The example below shows DSET1 using string variables and DSET2 using integers.
Table 59 - Supported Data Types for Data Log and Recipe Function Blocks (Continued)
Data Type Description Example Format in Output Data Log File
Data Log – Data Payload vs. Performance Time
Parameter
Number of Characters
28 502 518 1028 1493 3676
Average write time per data log 
file including all overheads
541.75 ms 1043.75 ms 1086.67 ms 1632.36 ms 1972.9 ms 2696.22 ms
Average write time excluding first 
sample
500.40 ms 963.86 ms 999.14 ms 1472.37 ms 1818.33 ms 2545.92 ms
Average write time excluding all 
overheads
479.10 ms 493.03 ms 502.78 ms 505.54 ms 519.91 ms 715.68 ms
Time (msec)
Data Payload
2750
2250
1750
1250
750
250
0
500
1000
1500
2000
2500
3000
3500
4000
715.68
519.9090909
505.5405405
493.0344828
502.7840909
479.10
541.75
963.858859
999.1414141
1043.75
1086.67
1472.367347
1632.36
1818.326531
1972.9
2545.918367
2692.22
Average write time per 
data log including all 
overheads
Average write time 
excluding first sample
Average write time 
excluding all overheads
500.40