Siemens S7-1200 - Program Instructions that Control Data Logs

Extended instructions
8.7 Recipes and Data logs
S7-1200 Programmable controller
382 System Manual, 03/2014, A5E02486680-AG
8.7.2.2
Program instructions that control data logs
DataLogCreate (Create data log) instruction
Table 8- 158 DataLogCreate instruction
LAD/FBD
SCL
Description
"DataLogCreate_DB"(
req:=_bool_in_,
records:=_udint_in_,
format:=_uint_in_,
timestamp:=_uint_in_,
done=>_bool_out_,
busy=>_bool_out_,
error=>_bool_out_,
status=>_word_out_,
name:=_string_inout_,
ID:=_dword_inout_,
header:=_variant_inout_,
data:=_variant_inout_);
Creates and initializes a data log file. The file is
created in the PLC \DataLogs directory, named
by the NAME parameter, and implicitly opened
for write operations. You can use the Data log
instructions to programmatically store run-time
process data in flash memory of the CPU.
STEP 7 automatically creates the associated
instance DB when you insert the instruction.
1
In the SCL example, "DataLogCreate_DB" is the name of the instance DB.
Table 8- 159 Data types for the parameters
Parameter and type
Data type
Description
REQ IN Bool A low to high (positive edge) signal starts the operation.
(Default value: False)
RECORDS IN UDint The maximum number of data records the circular data
log can contain before overwriting the oldest entry:
The header record is not included. Sufficient available
PLC load memory must exist in order to successfully
create the data log. (Default value - 1)
FORMAT IN UInt Data log format:
• 0 - Internal format (not supported)
• 1 - Comma separated values "csv-eng" (Default
value)
TIMESTAMP IN UInt Data time stamp format: Column headers for date and
time fields are not required. The time stamp uses the
system time (Coordinated Universal Time - UTC) and not
the local time.
• 0 - No time stamp
• 1 - Date and time stamp (Default value)