1 FUNCTIONS
1.12 Logging Function
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1.12 Logging Function
This function logs (records) digital output values or digital operation values. Data of 1000 points can be logged for each
channel. Logging data are stored in the buffer memory area. In addition, the data collection can be stopped by using the
status change of the data as a trigger. This function also helps the error analysis since the data before and after the
occurrence of an error is held.
Using function blocks (FBs) enables saving the data stored in the buffer memory as a CSV file.
Logging function
■Collecting logging data
Logging data is collected as follows.
• 1000 points of the latest digital output values or digital operation values can be always collected for each channel.
• The data can be collected at intervals of 10ms at a minimum and of 3600s at a maximum.
An address where the latest/oldest data is stored can be checked with the latest/head pointer.
Logging data are stored in the buffer memory area. When the number of stored data points is 1001 or greater, data is
sequentially overwritten from address 0 with new data.
■Stopping the logging operation
The logging data is refreshed at high speed during logging. Stop logging when the logging data needs to be referred without
paying attention to the refreshing cycle.
Logging can be stopped by the hold trigger.
• A hold trigger allows two options: Logging hold request or Level trigger.
• The number of data points to be collected after a hold trigger occurs can be set.
(1) Head pointer
The address of the oldest data in logging data can be checked.
(2) Latest pointer
The address of the latest data in logging data can be checked.
(1) Logging hold request
A hold trigger is generated from a program at any timing.
(2) Level trigger
A hold trigger is generated when a stored value in a buffer memory area is monitored and
the set condition is satisfied as follows.
Example: When the stored value exceeds or falls below the set value, a hold trigger is
generated.
(3) Post-trigger logging points
When the set points of data is collected after a hold trigger is generated, the logging
operation is stopped.
(1)
(2)
…
Digital output value
or
digital operation value
Logging
cycle
Address 0
Address 1
Address 2
Address 3
Address 4
Address 5
Address 998
Address 999
(3)
(2)
(1)
…
Hold trigger
Address 0
Address 1
Address 2
Address 3
Address 4
Address 5
Address 998
Address 999
Logging data are stored
in buffer memory areas.
Stored value of a buffer
memory area to be monitored
A trigger is
generated.
Trigger setting
value
A trigger is
generated.
Time
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