[Logix Designer] Check Ethernet device connectivity, when not declared in IO Config

[Nico38]

Hi all,

I use a "Remote access from Internet" device on my machine networks, to allow remote access to them, and therefore to the PLCs for remote assistance when necessary.

Some of my customer requests my assistance, and we loose precious time because it often happens that the remote access device is disconnected from machine LAN.
Some customers don't like to leave remote access to their machine nor plant all the time, so they disconnect the cable, and then forget it the day they really need it.

So, to prevent the case, I would like to display on the machine HMI the status of remote access device. How can I get the "connected" status from a device which is not declared in Logix Designer IO Configuration ?

Is there a way to "ping" a device IP address from PLC, or another solution to ensure that a device is connected to the machine network ?

 

[cardosocea]

Knowing more about said device would possibly open up some possibilities. Does it have an EIP or CIP interface? I have 3 drives at the minute being polled for used power by a PLC and none of them are in the HW tree for that PLC. You can get this through a message instruction. Perhaps your device has something similar?

Does the device have a fault switch? Perhaps configure the port being down as a fault for the switch and wire that into the PLC? (not practical since it incurs in costs, but a possibility).

If the device has a web server available, perhaps program a socket in Logix to open up port 80? You wouldn't need to send data across, just being able to open it would tell you there's something there.

 

[Nico38]

I am sorry for the lack of information about the said device, but the forum rules prevent me for writing the name of it, it is automatically replaced by ****.

The device is a basic VPN device that only permits to access to a network through internet. In most of the case, via a SIM card.
The device is not EIP or CIP. Let's compare it to a third party managed switch.

 

[cardosocea]

Even if you s-p-a-c-e o-u-t the letters? I'm curious to know which brand it is. LOL Even the model number would do and it's unlikely to have issues.

Perhaps looking at the option of sockets? Not great I think, but one possibility.

 

[MarkNightingale]

Looks like **********

 

[MarkNightingale]

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[Nico38]

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Yep, it is it ! Flexy model

 

[Ken Roach]

Unfortunately if the device doesn't support any CIP services, the ordinary ControlLogix MSG instructions can't communicate with it at all.

When the device is an EtherNet/IP capable device that just isn't in the I/O tree, then I use a CIP "List Identity" command; the device replies so I know it's online (like PING does for you) but also it lets me know I've queried the correct device.

To my knowledge, Logix doesn't implement an ICMP PING client.

If I was going to put in the work to do a TCP/IP socket connection (most modern Logix controllers support them) I would do an SNMP query to get a specific value like the vendor name from the device.

 

[chud]

Worst case scenario you can hardwire a signal from the Flexy DO to the plc

 

[Nico38]

Thank you all for your replies.

I am going to dig into the device's manual to see if I can use either Ken Roach solution (SNMP query to see if the device replies), or maybe in the future I will rather follow "the old style" way proposed by Chud : To use a wired DO.