Trips on LM2500+DLE Associated with MKVI and HMI.


Thread Starter


To give you some background:

We have an LM2500+ DLE (PGT25+) compressor train supplied with a PCL802 pipeline compressor, all supplied by Nuovo Pignone and running using a MK6 Controller.

This was installed around 1999-2001. The HMI and MK6 has never been upgraded/patched since installation. HMI PC is currently a 16 year old WindowsNT machine (cant find any manufacturer make or model).

The issue we are currently having, is extensive trips all related to one alarm - "Virtual Memory Full".

We are having the MK6 and HMI migrated to MKVIe next year which will obviously solve the issue. However, until then is there any way of reducing/fixing this problem without upgrading to the new HMI software package - i.e. Upgrading RAM, Virtualise on to new PC hardware?

Many thanks.

<i><b>In general,</i></b> the HMI does NO control or protection functions--so even if it is having memory issues, all that should do is prevent viewing/monitoring unit operation, prevent sending commands, and prevent seeing alarms and events being sent from the Mark VI controller(s). In other words, the HMI should NOT be tripping the Mark VI--ever. For any reason. Unless there's something really screwy about the set-up/configuration there, only the Mark VI--and select other <i><b>inputs to the Mark VI</i></b>--should be capable of tripping the turbine.

This "memory" alarm--is it actually coming from the WinNT HMI, or is it a process alarm from the Mark VI? Is it possible that when the unit trips there are so many alarms being broadcast from the Mark VI that the WinNT machine can't process them because of it's memory problems and that's why that alarm is coming up?

If I recall correctly, WinNT virtual memory refers to "paging" files on the hard drive. WinNT uses space allocated on the hard drive as memory (virtual memory) when it needs more than the available RAM can provide. So, if there are problems with the hard drive, that can cause virtual memory problems.

WinNT machines need to have their hard drives de-fragmented fairly regularly. Have you done this? This is just normal, accepted practice for WinNT/Win2K/WinXP machines (though the WinXP machines don't seem to have as many fragmentation issues). STOP TCI and CIMPLICITY (so do this when the unit isn't running), and then run the MS-Windows Defrag utility. There may also be some hard disk issues (bad sectors; etc.) which are contributing to the problem. But, do try to get them cleaned up and that should help with the HMI end of things.

My suggestion is to defrag the hard drive, maybe run a CHKDSK scan to look for and mark bad sectors to prevent them from being accessed. AND, get an IT professional to do this if you're not familiar with WinNT and these utilities. Unless there's a good hard disk image which can be used to recover from it's not very hard to unintentionally screw up the OS and hard drive--leaving you with a useless HMI.

But, again--unless there's something odd about the configuration at your site the HMI should never be capable of tripping the turbine--even if it's only having memory issues. Especially if it's only having memory issues. HMIs are just devices that allow the operator to view and monitor unit operation, send commands, and respond to Process and Diagnostic Alarms from the turbine control panel. While people refer to HMIs as "the Mark VI" (or "the Mark V" or the "Mark VIe")--they are NOT part of the turbine control and protection, only the turbine control panel does control and protection (under normal conditions and configurations). In fact, the turbine can run quite nicely without an HMI (once it's started), and I'm sure many operators would almost prefer it that way since many units experience a HIGH number of pesky and nuisance Process- and Diagnostic Alarms, which are displayed on the HMI and require clicking and such.

I would find it very unusual to learn that HMI memory issues are causing the unit to trip. Rather, I suspect that when the Mark VI trips the turbine or learns of a turbine trip (because it's possible the compressor control could be tripping the turbine) and then starts annunciating a lot of Process- (and possibly Diagnostic) Alarms that the HMI, if it was having virtual memory/hard disk--or even RAM!!!--problems would have a hard time displaying and keeping track of all of the alarms. Especially if, as some sites do, the alarms from other controllers in the plant are being displayed on the HMI being used for turbine control.

Please write back to let us know what you find!

And, I'm very distressed to hear that you are getting a "Mark VIe upgrade." GE has this new, ..., .... "system" that just replaces some cards in the Mark VI processor racks with Mark VIe-compatible cards and then uses ToolboxST and WorkstationST and ControlST on a new HMI to operate the turbine. It's NOT REALLY a Mark VIe, and it's not really a Mark VI, either. And, you will spend a lot of money over the next few years buying more and more upgrades as GE stops supporting more and more of the Mark VI hardware which isn't being replaced at this time. It's really a scam, and they're not telling people what they're really getting--and what it's really going to cost them in the long run.

If you're going to upgrade to Mark VIe--just DO IT.

But, I'm not sure anyone really wants to do that (upgrade to Mark VIe) right now--because, as produce life-cycles go the Mark VIe should be just about at the end of its life-cycle, so upgrading so close to the end of the life-cycle of the Mark VIe when the Mark VII is probably due in the next year or so.

Just sayin'.....