Problem with PI Performance Equation calculated tag

it seems that i forgot the very basic of PI tag attribute - Location1.

Thanks to Stephen from Osisoft who highlighted this issue, from the ICU the ID is set to 5 - therefore any tag getting the data from this PI-PE interface must have Location1 = 5.

Mark V - IO_CFG.LST Change Detection for SOE

in IO_CFG.LST u can check under TCDA card definition (just search for TCDA) u can see that the Chg Det is set to 1 (which is ENABLED).

Having this turned on for that particular card / contact input will enable Change Detection for SOE purposes.

On the other hand, u can check CONFIG.DAT to see whether SOE will be printed or not. Having SOE enabled does not necessarily required it to be printed (at least this is the case at PPSB Power Plant).

Creating a calculated PI tag using PI Performance Equation

So now, DOE requested for a reading from our CEMS system. They wanted a 30 mins average tag for NOx and CO reading.

PI Performance Equation can be used to provide average reading for CEMS_NOX and store it using new tag name.

In this case, we use a new tag called CEMS_NOX_2.

the most important part is to correctly specify the calculation formula under ExDesc attribute.

this is what i used.

TagAvg('CEMS_NOX','*-30m','*')

the format is actually...

TagAvg(tagname,start time, end time)

using PI Processbook, u can verify the tag's attribute..

Cloning VirtualBox VDI file

before cloning, make sure detach VDI file from its VM.

i need to periodically backup my precious VDI file (my VM) under VirtualBox. copy and paste the VDI will NOT work.

the correct way is to use vBoxManage tools.

vboxmanage clonevdi "e:\master.vdi" "e:\clone.vdi"

this is the command assuming your host is Windows. should ur VirtualBox is running on Linux - just remove the "

for example, 

vboxmanage clonevdi /usr/dindon/master.vdi /usr/dindon/clone.vdi