SLC5/05 Connection Question/Problem

[Firejo]

If the HMI is connecting to the 5/05 in question why can’t you simply go into the configuration of the HMI and see where it’s getting its data from? That should tell you the IP address of the SLC. The other thing you could do is connect the HMI to the SLC via a dumb hub (or a switch that won’t do any filtering) and connect the PC running wireshark to the same hub. Set it up so that only these three devices are connected and make sure the only thing running on the PC is wireshark. When the HMI talks to the SLC you should see the MAC and IP addresses of both devices.
The other question I have is, you setup RSLinx to connect to the IP address you believe the SLC to be set to but did you set the PC’s IP address to “172.16.0.x”? If the subnet does not match between the PC (running RSLinx) and the SLC you won’t get a connection.

 

[Oceansoul]

The Ethernet port is unused, no HMI or network connected.

Luke:

Since the PLC is communicating with a PC based HMI I figure it has to already received BOOTP from that PC. When I fired up BOOTP on my computer it wanted me to assign an IP address - which if I changed would screw up the HMI comm's I would think. And, I can't access the IP address that the HMI is talking to from the HMI PC.

With Wireshark still running the only Rockwell MAC address is the ARP Request, same one in the picture above with the same 2 WhoHas & Tell addresses that don't seem to be right.

???
There either is or there isnt a network and a cable in the ethernet port on the 5/05.

 

[Firejo]

Very good catch Oceansoul. Aabeck, what gives?

 

[Geospark]

Confusion reigns...

...If an hmi is on the ethernet network with it. You could open up its options and find out the subnet Ip addresses...

Is there a HMI on the network with it?...

...The Ethernet port is unused, no HMI or network connected...

No, and Ethernet port is unused...

...Got back to the customer this morning, fired up Wireshark - connected to the switch in the panel. Ran over 45 minutes with 1000's of entries for my laptop & the computer running the HMI...

Now there is an Ethernet switch in the panel and a PC based HMI...

...Since the PLC is communicating with a PC based HMI I figure it has to already received BOOTP from that PC...

So now it's communicating with a PC based HMI on the Ethernet network...

If the PLC is connected to an HMI can you not open that program and see what communication protocol it is using and then disconnect the HMI and connect to t he PLC to do an upload...

Similar suggestion to DwSoFt's...

The HMI is run on Proficy iFix, and the normal windows functions are not accessable with iFix running, like can be done on other HMI programs - I would have to shut the line off, something the customer doesn't want today...

But now the answer is not...

"...The Ethernet port is unused, no HMI or network connected...",

but rather...

"The HMI is run on Proficy iFix...I would have to shut the line off..."

You are all over the shop with your details and not following the good advise you are getting.

The MAC address prefix of "00-00-bc" is exclusive to Rockwell devices. When you see "00:00:bc:2a:16:b9", it is the same as when you see "Rockwell_2a:16:b9"

You have confirmed from the side of the SLC that its MAC address is "00:00:bc:2a:16:b9", so any other MAC addresses you see in Wireshark are not your SLC.

You have shown to us once (in Post#21) that your SLC MAC address made a BOOTP request for an IP address, and that it is currently at the default of no IP or Subnet Mask being set (0.0.0.0 / 255.255.255.255).

In Post#24, from Wireshark, you are seeing an ARP request from "Rockwell_30:15:96", another Rockwell device on this network i.e. not the SLC, which has an IP address of 172.16.0.211. It is looking for the MAC address of 172.16.0.1.

The computer is not, so what other Rockwell devices are on this network? Is the switch in the Panel a Rockwell switch?

As has been mentioned, what is the IP address of your programming laptop?
As Ken advised, use "IPCONFIG /ALL" at the Command Prompt to find this out.

Also important, what is your programming laptop's Subnet Mask set to?

It looks like this localized network is using the 172.16.0.x range. If your laptop's IP address is set to 172.16.1.x, and its Subnet Mask is set to 255.255.255.0, then its x.x.1.x address cannot reach the x.x.0.x addresses. You would need a Subnet Mask of 255.255.0.0 to achieve this.

Why do I think your laptop is using 172.16.1.x?

Because in your RSWho window, in Post#24, you can see "Browsing - node 172.16.1.151 found". I wonder what that could be?

I think your laptop is using 172.16.1.x and the common Subnet Mask 255.255.255.0, which will prevent RSLinx from browsing to 172.16.0.x addresses.

The Yellow question mark stroke Red X addresses in RSLinx, 172.16.0.1 and 172.16.0.211, are remnants from a browse where you either had your laptop IP address on x.x.2.x for a while, or you had the Subnet Mask set to 255.255.0.0 for a while.

If your confirmed SLC MAC address has BOOTP requested an IP address, then, at least at that point in time, it could not have been communicating with anything, let alone a HMI computer.

Also, it will most likely have not gotten an IP address from the HMI computer, as it will most likely not be acting as a BOOTP Server. Therefore, worrying about loosing comms between the SLC and a HMI computer appears to be irrelevant?

I see now Oceansoul has also cottoned on to the same as me...

G.

 

[Aabeck]

Sorry guys,

Should have said this morning that when I got to the customers shop the unit with the SLC5/05 I was trying before was powered down for maintenance & he let me spend time on another machine with a 5/05 & an HMI to see if I could connect to it. The posts today are about this new machine

 

[Geospark]

That's no problem, but have you any feedback on what's been posted since you last replied?

They can't all be "faulty". You are doing something simple and fundamentally wrong, or changing to much at the one time.

Start with telling us the laptops current configuration...

G.

 

[Aabeck]

Geospark,

I'm running an XP Professional laptop with a built in serial port, so I don't have any issues with a USB/Serial adapter on this computer for the DF1 comm's.

I have RSLinx ver 3.70 & RSLogix500 ver9.00.

The MAC address is: 00:21:70:96:4D:92
The reported IP address is: 169.254.61.180 (for the wired Ethernet connection, another for the wireless)
The Subnet is: 255.255.0.0

Reading back about the 204 error, should I manually change the IP address of the laptop to something like: 192.168.0.13 to be in the same group? And the subnet group 3rd number to 255? My working on networks is very limited & this Ethernet setting-up is new to me.

 

[Geospark]

...The reported IP address is: 169.254.61.180
The Subnet is: 255.255.0.0...

...should I manually change the IP address of the laptop to something like: 192.168.0.13 to be in the same group? And the subnet group 3rd number to 255?

169.254.1.0 through 169.254.254.255 are reserved for stateless autoconfiguration addresses. They are normally only used to assign IP addresses to network interfaces when no external, stateful means of address configuration exists, such as the Dynamic Host Configuration Protocol (DHCP). Windows refers to this as "Automatic Private IP Addressing (APIPA)". It is sometimes also casually referred to as "Auto-IP".

I don't know where your laptop has been, but at some stage recently it was plugged on an Ethernet network with DHCP enabled, but could not find a DHCP Server to assign it a stateful address. It was then given an Auto-IP address of 169.254.61.180. This often happens on Industrial networks when the computer's port is not assigned a Static IP address before joining the network. This address is of no use to you.

Why use 192.168.0.13?

192.168.x.x has not shown it's head here yet, and also this network appears to have been configured for a non-standard IP range.

172.16.0.100 would be a good starting point for your laptop's Static IP address as there appears to be two devices using that range already. When you have set that IP address, check it has held by looking at the LAN properties for your adapter (icon on task bar), or do another "IPCONFIG /ALL".

Leave the Subnet Mask at 255.255.0.0 as this will allow your laptop to "see" both subnets (x.x .0.x & x.x.1.x).

I'd open BOOTP and set the same subnet. The gateway address shouldn't be needed as your browsing locally, hopefully.

Then see do you get any BOOTP requests from your SLC's MAC address.

G.

 

[Aabeck]

Why use 192.168.0.13?

Thanks,

I was looking at a picture of the previous unit I was trying to connect to, it was coming up with an IP of 192.168.0.9.

Looked at the latest pic & it shows 172.16.0.211, so when I get back to the customers shop I'll try whichever IP matches the PLC connecting to.

As far as getting the existing IP, my laptop has been to a lot of shops, but up until now either they weren't 5/05's, or the customer knew the IP address or it was written on the PLC itself (a good idea).

 

[Geospark]

...I'll try whichever IP matches the PLC connecting to...

If you knew that, my friend, none of us would be here!

You don't know the PLC IP address, if it even has one at the moment, but I'm sure you meant the IP address "range" you were seeing when last on the same network as the SLC.

...I was looking at a picture of the previous unit I was trying to connect to, it was coming up with an IP of 192.168.0.9..

Ah ok, yes, it was back on the original machine you were seeing the 192.168.0.x range. We didn't get a screenshot of that. The 172.16.0.x IP range is on the second machine's network that you were testing on.

Yes, when you are back at that first machine, set your laptop to a fixed IP address within the 192.168.0.x range, but I would go higher than the 192.168.0.13 address you mentioned in case of duplicate addresses. I usually go to x.x.x.100 for small networks as it's unlikely there will be anything that high. Again just leave your Subnet Mask at 255.255.0.0.

Then hopefully you will pick up the BOOTP requests from the SLC again. You could check for this again in Wireshark first, or just go straight to BOOTP Server and see are you getting requests from the SLC's MAC address 00:00:bc:2a:16:b9. If nothing in BOOTP, then go to Wireshark. Where you go first is up to you.

By the way, your laptop is a Dell? The MAC prefix: 00:21:70 is one of the many assigned to DELL Inc.

I've also noticed back in Post#21 on the bottom line, when you were getting the SLC BOOTP requests, there was something else requesting a NetBIOS Name Search with a stateless Auto-IP address of 169.254.120.228. Your laptop again perhaps? Do you know the MAC address of that device to compare to your laptop's MAC address?

If your laptop had a stateless 169.254.x.x IP address at the time Wireshark was picking up the SLC broadcasting BOOTP requests, then your laptop could not have serviced those requests using the BOOTP Server software, had you tried it.

Also, browsing to devices in RSLinx would not work correctly either.

It's starting to look like all your issues are to do with you leaving your laptops LAN settings on dynamic (DHCP), instead of static. Small localized industrial networks don't always have a DHCP Server to administer IP addressing and so you should be assigning your laptop a suitable static IP address when browsing them.

G.

 

[Aabeck]

Geospark,

Thanks for the info. Yes the XP laptop is a Dell (I just had to recently buy due to my new laptop runs Windows 8.1 64 bit & won't run a lot of the software I had - so I reverted to XP for field use).

Another question I just thought of - does the PLC retain the IP address it gets from BOOTP upon power down, or does BOOTP have to be run every day when I try to connect?

And the other IP address is assigned to my wireless connection.

 

[Geospark]

...does the PLC retain the IP address it gets from BOOTP upon power down, or does BOOTP have to be run every day when I try to connect?...

In BOOTP Server, when setting the IP address for the controller, you have the option to disable BOOTP. The controller will then retain its IP address through power cycles. If not disabled, then yes, it will loose it's IP address and start sending BOOTP requests again.

...And the other IP address is assigned to my wireless connection...

Don't worry about your wireless connection. I would disable your WiFi while browsing fixed media networks. It can add to the already present confusion!

G.

 

[Aabeck]

Thanks, I'll make sure to disable that after I set it, and write the IP address on the PLC itself.

And here's hoping your turkey wasn't too dry.

 

[Aabeck]

Well, I got to connect to the 2nd SLC5/05 today through Ethernet. I did a system comms upload to make sure I got the channel config's, and it showed channel 0 as DF1 Full Duplex, 19000 baud, standard config - but when I again tried to connect to it through DF1 RSLinx still won't see it. I tried a nearby SLC5/04 & connected fine, so it's not a computer, serial port, or cable problem. Puzzling. Unless the RS232 port on the 5/05 is dead?

The other SLC5/05 the customer wants uploaded was still down for repair, but neither I nor the customer had a switch or crossover cable, have to buy one this weekend.

 

[Aabeck]

Got back to this shop today for a different reason, but when I finished I re-tried to check the SLC5/05 I finally connected to. Previously I gave it an IP address & then disabled BOOTP so it retained it.

Today I tried from scratch to come up with the IP, but Wireshark ran for hours without ever showing the IP or the Rockwell MAC address. I was trying to see what to expect when connecting to a new 5/05. This is the one without anything connected to the Ethernet port.

I then went into RSLinx, added the IP to the Ethernet driver, and RSLinx immediately saw it. Then checked Wireshark & it lit up with lots of comm's between my laptop & the PLC.

Should the 5/05 have sent something out for Wireshark to see before RSLinx talked to it?