We have a Mark VIe panel on a steam turbine with a mechanical drive. We have 3 LVDTs on V1 and 3 LVDTs on V2 on the PSVP cards. How do you view the live LVDT voltages? On Mark VI, the LVDT voltages were accessible via telnet. We tried to connect telnet but log on and password previously used for Mark VI did not work. Is telnet the correct way to view the voltages or is there another way to view the voltages via the HMI for the Mark VIe?

 

In Mark v it can be possible in the Auto calibrate screen. I not sure about Mark VIe.

G.Rajesh

 

Hi,

MarkVIe controllers do support TELNET session. The TELNET is basically a window utility to interact with the controllers. You can also do a telnet session with the MarkVIe Controllers, but you need to rum llm (low level Monitor) commands to interact with the MarkVie controllers. In MarkVI it is the tsm (terminal session monitor) which interact with the controllers. So in MarkVI it is tsm session and MarkVIe it is llm session to talk to the MarkVIe controller. The TELNET is the utility program through which you start the tsm session and llm session with the MarkVI and MarkVIe controllers. I am not sure If you are aware of the llm session. Without that you cant interact with MarkVIe controllers and also with the I/O packs.

Note:- Improper use of llm commands leads to the dangerous consequences and it can trip the turbine too. So until and unless you are sure what llm commands need to run, please do not use it and use the toolboxST to view different parameters.


You can use TELNET/LLM to view the LVDT volatges while doing the calibration. For this you need to to a remote llm session with the PSVO (SERVO I/O Pack) and go to "app*lication" and then to LVDT to view the LVDT voltages. In the toolboxST also there is a provision to see the LVDT voltage. I can’t remember if it is the position or the voltages that you can directly view in the toolboxST. Open the MarkVIe device, go to the servo I/O pack, go to the LVDT tab and see what you find there.

Hope this helps.

Thanks
MarkVIe Guy

 

I really don't recommend using llm, though it is possible to get to the LVDT voltages that way. It is not a tool intended to be used by anyone outside of the controller development team; many commands in it can disrupt normal controller function without any warning.

It should be possible to get the same data from ToolboxST, though I don't have a PSVP to double check this with. Open the Mark VIe device in ToolboxST, and in the Hardware tab go to the PSVP in question and select its Regulators tab. There should be a "Calibrate Valve" button. Click it to bring up the Calibrate Valve dialog, which shows the LVDT voltages.

 

Thank you for the quick response. The unit has not been commissioned yet, but we wanted to create a procedure for viewing the live LVDT voltages during the upcoming FAT. This will ease the valve calibration effort during the installation. I am assuming the password will be root just as in the case of the Mark VI, if not, hopefully we can get some additional assistance from GE technical support.

Thanks again.

 

Please don't use llm as it carries too much risk. There is a feature called Monitors that can be used for this. You can find it in your servo card configuration. Hint: right click to add one. You can create one for each of your LVDTs. The scaling is usually used to convert volts to position, but if you want volts, try a scale of 1 to 5 for a display of 1 to 5. It works nicely and lets you see the values when online.