When attempting to address a high temperature observed in the diffuser section of one of our GE7FA gas turbine units our control room operator was unable to initiate a start or a swap from lead to lag on the 88BD exhaust diffuser fan motors from either of our two units HMI systems located in the control room. The following error message was presented to him when attempted:

The point \\GEWORKSTATIONST\GT2.LAG1BD_CPB is read only

does anyone know how to change this from read only to active so that we can manipulate it from the control room HMI? Also anyone have any ideas as to a root cause of why this is now set this way?

Thanks to all

 

Norm,

Is this one of those Mark VIe upgrades of a Mark V that came with new and/or upgraded HMIs?

You seem to be saying that in the past (how long ago?) the operator <b>was</b> able to change diffuser blower motors from at least one of the control room HMIs (pre-upgrade if the control systems and/or HMIs were upgraded?). Is that correct?

If it definitely worked previously with these HMIs and the Mark VIe (operators always insist, "That's NEVER happened before!" when complaining about something, and come to find out it's always happened--or it can't be verified to have worked correctly since commissioning) then the only way it could have gotten changed is if someone mis-edited the EGD list in ToolboxST, then compounded the problem by updating the HMI .hmb file from ToolboxST. It would likely have required a download to the Mark VIe because of at least a minor difference, if not a major difference. And, it's odd that only this logic signal would have it's read/write status changed--and only on one of two GTs.... Does it work on the other GT.?.?.?

But, someone familiar with defining logic signals in ToolboxST EGD pages and then updating .hmb files is going to have to check the signals to see if they are configured properly.

Most likely.

Please write back with update(s) and a resolution.