Hi all,
I am having a major fault on a S7-200. The fault always happens on weekends when no one is there to assest the situation and the plc is in a federal goverment building where it is not accesible on weekends. Every monday morning, an operator cycles power to the plc as they need the booster pumps to run for the week. If I look at the S7-200 manual, it says there is a history log of major CPU events but a colegue of mine tells me that the plc clears the history log when power is cycled. I am looking for a second oppinion as my colegue's info was from a shady source and not from experience.
From the manual:
"The S7-200 maintains a log that contains
a time-stamped history of major CPU
events, such as when power is applied,
when the CPU enters RUN mode, and
when fatal errors occur. Your time-of-day
clock must be configured in order to get
valid time and date stamps on the log
entries."
It says nothing about the power having to stay on to keep the logs. I know they say 'maintains' but it can be interpreted many ways. I thought that having a working baterry would keep the history log buffer alive, even on a power outage(in this case a 5 sec power outage) so that the logs are still available after a power loss.
Any insight here is apreciated.
Also, any insight as to why the plc is getting faults only on weekends would also be apreciated.(there are timers in the program but maximum timer time is 25 mins and nothing to my knowledge is different(inside and outside variables) from weekdays to weekends) It might also be a weird coincidence but it has happened 3 weekends in a row.
Thanks!
I am having a major fault on a S7-200. The fault always happens on weekends when no one is there to assest the situation and the plc is in a federal goverment building where it is not accesible on weekends. Every monday morning, an operator cycles power to the plc as they need the booster pumps to run for the week. If I look at the S7-200 manual, it says there is a history log of major CPU events but a colegue of mine tells me that the plc clears the history log when power is cycled. I am looking for a second oppinion as my colegue's info was from a shady source and not from experience.
From the manual:
"The S7-200 maintains a log that contains
a time-stamped history of major CPU
events, such as when power is applied,
when the CPU enters RUN mode, and
when fatal errors occur. Your time-of-day
clock must be configured in order to get
valid time and date stamps on the log
entries."
It says nothing about the power having to stay on to keep the logs. I know they say 'maintains' but it can be interpreted many ways. I thought that having a working baterry would keep the history log buffer alive, even on a power outage(in this case a 5 sec power outage) so that the logs are still available after a power loss.
Any insight here is apreciated.
Also, any insight as to why the plc is getting faults only on weekends would also be apreciated.(there are timers in the program but maximum timer time is 25 mins and nothing to my knowledge is different(inside and outside variables) from weekdays to weekends) It might also be a weird coincidence but it has happened 3 weekends in a row.
Thanks!