User manual

Toolbox 32 User Manual 1.47d www.cse-semaphore.com/mykingfisher
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115
Example - Event Logging
Event Log Pointers
Event logs are kept in a circular buffer that is Max number of logs long (as defined in the topic Configuration -
Memory). When the buffer is full, the oldest logs are overwritten. The RTU uses an internal current pointer to
point to the latest log added to the buffer.
If an outstation RTU sends its event logs to more than one master RTU, the outstation should use a different
pointer for each master RTU. This allows the initiating RTU to know how many event logs it has sent to each
RTU.
Moving Event Logs Through An RTU Network
Event logs can be transmitted over an RTU network and accumulated in the master RTU. The event logs
from all the outstations are stored in the one event log buffer in the master RTU.
It is not advisable to have the master RTU requesting logs and the outstations sending logs in the one
system. This is because the event log pointers in the master RTU and in each outstation RTU will not be
synchronized and the event logs already sent by the outstation will be requested again by the master and
vice versa. This results in two identical event logs in the master for each outstation event log. Therefore
event logs should only be moved in one direction (ie. either the outstations can send the event logs OR the
master can poll the event logs).
Generating Event Logs
Before generating event logs, some memory must first be allocated for storing the logs (please see the topic
Configuration, Memory, Event Logs. Eg. 32kB of memory can store 2730 logs). Event logs can then be
generated using ladder logic as shown below.
│ │
├Log Tank Level Every 10 minutes ┼ ┼ ┤
│ │
│DoEvery10min LogTankLevel │
│#YTICK.10MIN Type 1 │
├─────┤ ├──────────────────────────────────────────────────────────(Event Log)─┤
│ #AI14.2 │
│ │
├Log Digital Input channel on change of state ┼ ┤
│ │
│NewDigInput LogDigInput │
│ #DI15.1 Type 1 │
├──[CHANGE]────────────────────────────────────────────────────────(Event Log)─┤
│ #DI15.1 │
│ │
Figure: Generating Event Logs