Unable to change Preferred Media Mode on cFP-2220

[Allan5656]

I am using a cFP-2220.  Using NI MAX, I want to change the Preferred Media Mode under Advanced Ethernet Settings to '100 Megabit/Full duplex' but all options are disabled except 'Autonegotiate'.

Can someone explain why this is?  I will supply any details needed to answer this question.

Thanks,

Allan

[Thør]

I'm interested in which port you're using to communicate back to your computer (or through the network back to the computer).  Can you also tell me which version of the Fieldpoint drivers you currently have installed?

[Allan5656]

Software installed on cFP-2220: 

FieldPoint 6.0.3 - Sep 2008 package:
  DataSocket for LabVIEW Real-Time 4.5.4
  FieldPoint Drivers 6.0.3
  FieldPoint VI Manager 6.0.3
  LabVIEW Real-Time 8.5.1
  Modbus I/O Server 1.4.1
  Network Variable Engine 1.4.1
  NI-Serial RT 3.3.2
  NI-VISA 4.4
  NI-Watchdog 3.0.0
  Variable Client Support for LabVIEW RT 1.4.1

As for the port information, I am waiting for information from our IT department about which port is used.  The LabVIEW app running on the cFP uses port 5555 for TCP communications with LabVIEW apps on PCs.

I will update this as soon as I hear from IT.  Is there an easy way to find out which port it is using?  (like a "ping" command)

Thanks,

Allan

[Thør]

I'm sorry, I should have been more clear about that.  I was wondering which physical ethernet port on the cFP2220 you had the ethernet connected to, either port 1 or port 2.  If you're having IT check your network's ports, you should have them verify that port 44525 is open for communication, since this is the port the cFP uses to communicate its information back to MAX.  The other ports you should have open are outlined in this KnowledgeBase article.

Another thing we could try is updating the FieldPoint drivers to the newest version.  The new version supports your hardware for all versions of LabVIEW from 7.1 - 2011.  Updating it may fix this issue.  Let me know if any of these steps help at all.

[Allan5656]

I am using LabVIEW Real-Time 8.5.1, so I installed FieldPoint 6.0.8.  I now have NI MAX 4.7.6 installed, and the field is now called 'Preferred Link Speed" which is set to "Autonegotiate"; there is no drop-down list.

Allan

[Thør]

Using one of the 2220s I have here, I do not have this drop down box either.  Autonegotiate should pick the link speed that is compatible with your current network and setup.  Is there a reason why you wouldn't want this to automatically configure?

[Texas_Diaz]

The network driver on the cFP-2220 does not support manually setting a preferred link configuration.  On the target, the driver tells MAX what it supports, and MAX blanks out all of the configurations that are not supported.  This is usually done in order to force a slower speed than would be normally negotiated by your network; unfortunately the cFP-2220 drivers do not support this.

-Danny

[Jeff.F]

Kyle,

     I'm also interested in forcing the link speed to 100Mbps or 10Mbps.  Our network is using DSC and we are getting "Bad Status" errors with no timestamp.  This occurred with 1804's and 2220's and is especially bad because you cannot acknowlege a bad status that does not have a timestamp.  Well, the "Bad Status" errors indicate that they are due to server disconnects and we postulated that maybe some of our connections are renegotiating causing the disconnect and server timeout.  I have seen in the past where Ethernet connections will renegotiate connection for an unknown reason (probably a cable that is borderline for Gigabit or 100Mbit.)  My bandwidth is sub 10Mb so I could drop the cFP speeds down to a speed (10Mb) that is less susceptible to noise thereby avoiding renegotiations, disconnects, and server disconnects.  Another though was to set it to 100Mbps avoiding anything that included the word "auto."  The thought was that the interface would react to a comm error by doing nothing and staying on the same speed or that reconnect at the same speed would be much faster than restarting at the highest (1000M) and stepping down until a good link is acheived.  We are also raising the connection timeout which should also help.

Danny,

     You mentioned that the cFP & MAX negotiate the link speed.  MAX runs only on a PC, yes?.  What if there is a switch in between the MAX PC and the cFP.  There are two connections to negotiate.  How would MAX and the cFP involve the switch in negotiations and/or know which segment is being negotiated?  ...Or what if there was no PC/MAX on the network at all.  I believe that the cFP negotiates link paramaters directly with the device that it's connected to, regardless of what any instance of MAX does.  MAX only gives me the ability to interrogate and adjust cFP settings....which leads me back to... Why can't I set the "Preferred Link Speed" field to something other than auto?  I'm thinking it's just a driver shortcoming.  My drivers are;

FieldPoint 6.0.9,

NI Application Web Server 1.1

NI System Configuration network support 1.1.6

NI Web-based Configuration and Monitoring 1.0.1

Is there any hope for finding a driver that allows forcing speed?

Jeff Francis

Integration Engineer

Mink Hollow Systems Inc.

[Texas_Diaz]

Jeff,

I apologize if I did not make myself more clear.  Purely for the purpose of populating the drop-down dialog, MAX communicates to the cFP-2220 and requests all its supported modes, and grays out any modes that the device didn't respond that it supports.  The cFP-2220 specifically does not have the ability to change its preferred media mode - the network driver provided by the network device manufacturer does not support setting a preferred media mode, therefore it can only allow autodetection of the link speed. Network drivers that we write ourselves generally do have this feature (most of our PXI plug-in boards and built-in NICs have this). 

In order to customize the link speed, you will need to use a managed ethernet switch that can force a speed/duplex (like an NI MES-3980, or if you don't need an industrial rating you can go with a consumer managed switch like the Cisco SRW2008).

-Danny

[Texas_Diaz]

Jeff,

Also, as an aside, like any other device the cFP-2220 can only negotiate a link with its immediate link partner; it has no control of any of the other nodes down the line; even with devices that can support the preferred media mode, this setting merely suggests the media mode to use, and if the link partner cannot handle that mode then the mode is autonegotiated (nothing is ever "forced").  If you have multiple switches between the device and the end node, it's impossible (without dedicated custom hardware) to control the link speed across all of the nodes between one point to another.  However, the cFP-2220 specifically does not have the ability to change its preferred media mode - you are correct that the network driver provided by the network device manufacturer does not support setting a preferred media mode, therefore it can only allow autodetection of the link speed. Network drivers that we write ourselves generally take more time and are more difficult to write, but as an added plus we do add this feature (the majority of our PXI plug-in boards and built-in NICs have this). 

-Danny