Experimental Physics and
Industrial Control System

Matthew,

 

> I've not seen the problem with 5 terminal commands crashing the web

> server.

 

Just to be clear on this.  When the XPS is in this "bad state" executing a SINGLE terminal command crashes that XPS (vxWorks) Web server.  One then has to disconnect that Web client, i.e. open a new browser window. One can do this up to 5 times, at which point all 5 Web servers that the XPS normally starts at reboot are dead.  One has to reboot the XPS to get Web services running again.  After a reboot things are fine, executing terminal commands does not crash the Web server until something (unknown) puts the XPS into that "bad state" again.

 

The XPS runs vxWorks, and one can get to the vxWorks prompt.  When the Web servers die I believe that the following lines in the output of the "i" command

 

tHTTPd     18d8e8        764f644 200 PEND+T       13d43c  764f4e0  3d0004 6113216

tHTTPd     18d8e8        754f4b0 200 PEND+T       13d43c  754f34c  3d0004 6113212

tHTTPd     18d8e8        744f31c 200 PEND+T       13d43c  744f1b8  3d0004 6113214

tHTTPd     18d8e8        734f188 200 PEND+T       13d43c  734f024  3d0004 6113205

tHTTPd     18d8e8        724eff4 200 PEND+T       13d43c  724ee90  3d0004 6113201

 

will show that one or more Web server tasks as suspended.

 

Unfortunately they disabled many of the most useful vxWorks diagnostic commands, such as "spy" and others.

 

Mark

 

 

 

-----Original Message-----
From: Pearson, MR (Matthew) [mailto:[email protected]]
Sent: Monday, October 13, 2008 10:49 AM
To: Mark Rivers; [email protected]
Cc: Johnson, IP (Iain) - DIAMOND; Hudson, L (Lee); Nutter, BJ (Brian); Peter Eng; Vitali Prakapenka
Subject: RE: Newport XPS motion controllers

 

 

Thanks Mark. We do indeed have an emergency stop switch wired up, so

that is something to check.

 

I just tested this on our test XPS box. Unplugging and reconnecting the

'inhibit' blue connector puts all axes into state 2.

 

I've not seen the problem with 5 terminal commands crashing the web

server. Although we rarely execute that many commands in one go, without

switching to another panel or logging out.

 

At the suggestion of Pete Jemian we're also looking into network

monitoring. We have had problems in the past with the Nagios scanner

crashing the webserver.

 

We also plan to unset the default route address on all our XPS boxes.

Each beamline has it's own subnet, so this will help isolate it from any

outside network traffic.

 

Cheers,

Matthew

 

 

 

 

> -----Original Message-----

> From: Mark Rivers [mailto:[email protected]]

> Sent: 13 October 2008 14:16

> To: Pearson, MR (Matthew); [email protected]

> Cc: Johnson, IP (Iain) - DIAMOND; Hudson, L (Lee); Nutter, BJ

> (Brian); Peter Eng; Vitali Prakapenka

> Subject: RE: Newport XPS motion controllers

>

> Hi Matthew,

> 

> At our beamline at APS we have 5 XPS controllers.

> 

> I don't think we have seen problem 1).  Do you have an

> emergency stop input switch hooked up?  If so maybe you are

> getting noise on it, and it is a "real" signal in this sense?

> 

> I have seen something that may be problem 2).  The XPS gets

> into a state where if one executes any command usng  the

> "Terminal" screen in the Web page then it kills the Web

> server.  There are 5 Web server tasks running in the XPS, so

> if this is done 5 times then there are no longer any Web

> servers available.  I don't know what gets the XPS into this state.

> 

> We also have a problem that you have not mentioned.  Every

> couple of weeks the XPS and EPICS stop communicating, like

> the socket connections have been closed.  At this point the

> XPS Web pages still work.  I believe that it does not work to

> just restart EPICS, but rather one must reboot the XPS and

> then EPICS.  But I am not 100% sure of this, it may be that

> just restarting EPICS would fix the problem.

> 

> Mark

> 

>

> ________________________________

>

> From: [email protected] on behalf of Pearson, MR (Matthew)

> Sent: Mon 10/13/2008 5:19 AM

> To: [email protected]

> Cc: Johnson, IP (Iain) - DIAMOND; Hudson,L (Lee); Nutter,BJ (Brian)

> Subject: Newport XPS motion controllers

>

>

>

>

>

> Hi,

>

> I'd like to find out how many sites are using the Newport XPS

> 8-axis motion controller. At Diamond we have at least 10 of

> these controllers, on different beamlines, used mainly for

> diffractometers.

>

> We have been having some operational problems with them, and

> I'd like to find out if anyone else has had the same problems

> and if there was a solution.

>

> The problems are:

>

> 1) Controllers 'resetting' themselves, and putting all axes

> into state 2 (uninitialized due to an emergency stop). There

> tends to be a 'General Inhibition' error on all axes in this

> case. The controller does not reboot. This has happened

> several times recently on different beamlines.

> It has happened during the day and night, when the controller

> was in use and when not in use. It happened once during a

> homing procedure.

>

> 2) Webserver crashing. The webserver task seems to be

> suspended. In the past I have observed this to happen when

> the controller configuration is incorrect (for example,

> unplugging a motor and then rebooting - the webserver can

> fail to work). But it can happen at any time, when no

> configuration change has taken place.

>

> Often the EPICS driver continues to work in this case, and we

> can use a home-grown Python application to talk to the

> controller. So it really is just the webserver having a problem.

>

> 3) Webserver displaying incorrect information. Often the main

> control webpage can display the incorrect axis state, and can

> be observed to alternate between states on a seemingly random basis.

>

>

>

> Problem 1) is the most serious, and we are in the process of

> installing power supply monitoring equipment on one beamline,

> on the advice of Newport. However, the PSU is already well regulated.

>

> Has anyone else had similar issues with the Newport XPS?

>

> We're running various versions of XPS firmware on beamlines.

> Mainly 2.1.X, 2.3.X and 2.4.0. In all the controllers we have

> various selections of amplifier cards, but mainly DRV01 and

> DRV03. Most of the controllers tend to be almost fully

> populated with amplifier cards, and are installed in racks in

> air conditioned rooms.

>

> Regards,

> Matthew

>

> DLS Controls

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