OkiePC
Lifetime Supporting Member
Is the maximum scan time display updated by the SLC CPU after every scan?
EDIT: NEVERMIND...OBVIOUSLY WHEN I GO ONLINE AND READ 993 ALREADY IN THE Status file, the SLC keeps it accurate...but...
What would cause an extremely high First scan time?
I have a CPU that has always had a 992 to 996 ms first scan time, and I have studied it closely.
I am still baffled as to why, after finding a First_Scan driven loop and working it completely out of the code, the scan time remains unchanged.
The SLC 5/04 scans at 25-50 ms all other times. EDIT: The watchdog is set for 1000ms. It has never "watchdog" timed out in my nine months here! I have seen it hit 996 after amonth of daily checking. Happens every morning on power up, as well as returning to remomte run mode...every time First_Scan is true, the max reading hits within 8ms of the watchdog, I clear it, and it never again goes above 50 until the next First_Scan.
I suspect it could be I/O or comms related?
There is a pretty heavily populated devicenet control network and around 20 local slots in use. All 30 are enabled.
There are only two nodes on the local DH+ (PV1000 standard, 500ms scan freq. ~300 tags, ~50 alarm bits)
There is also a Net-ENI module connecting it's CH0 to the engineering lab network which could be a factor?
Any ideas AB experts?
I am at home so I can't post the code...
EDIT: NEVERMIND...OBVIOUSLY WHEN I GO ONLINE AND READ 993 ALREADY IN THE Status file, the SLC keeps it accurate...but...
What would cause an extremely high First scan time?
I have a CPU that has always had a 992 to 996 ms first scan time, and I have studied it closely.
I am still baffled as to why, after finding a First_Scan driven loop and working it completely out of the code, the scan time remains unchanged.
The SLC 5/04 scans at 25-50 ms all other times. EDIT: The watchdog is set for 1000ms. It has never "watchdog" timed out in my nine months here! I have seen it hit 996 after amonth of daily checking. Happens every morning on power up, as well as returning to remomte run mode...every time First_Scan is true, the max reading hits within 8ms of the watchdog, I clear it, and it never again goes above 50 until the next First_Scan.
I suspect it could be I/O or comms related?
There is a pretty heavily populated devicenet control network and around 20 local slots in use. All 30 are enabled.
There are only two nodes on the local DH+ (PV1000 standard, 500ms scan freq. ~300 tags, ~50 alarm bits)
There is also a Net-ENI module connecting it's CH0 to the engineering lab network which could be a factor?
Any ideas AB experts?
I am at home so I can't post the code...
Last edited: