RSLinx Connection Problems

We have a system that connects to various models of Allen Bradley PLC's ControlLogix, MicroLogix, SLC 5/05's. The system was commissioned and working fine.

I sent the plant this notice: ICSA-13-095-02A: Rockwell Automation FactoryTalk and RSLinx Multiple Vulnerabilities

The AB rep provided an update for the wrong version of RSLinx and everything in RSLinx lost communication. I wasn't involved up until this point so I am uncertain of the specific RSLinx Classic version, but this is where the issues start.

The majority of the plcs and the PC running RSLinx are on a network range of xxx.yyy.128.zzz One specific plc is on the network xxx.yyy.126.101. (This is a 5/05 PLC)

We have an old box running Windows XP with RSLinx 2.42 All communications work fine right now. (There are approximately a dozen communicating PLC's on the xxx.yyy.128.zzz and xxx.yyy.126.101 is communicating.)

We completely removed RSLinx from the Windows 7 box. We installed RSLinx 2.57 and configured the drivers. All devices that we configured in the xxx.yyy.128.zzz are communicating, the only one that does not is the xxx.yyy.126.101.

I actually pull the network cable out of the XP box and plug in the 7 box. All network adapter settings are the same between XP and 7. All driver settings in RSLinx are the same between XP and 7. Windows firewall is turned off. I can tracert to all plcs successfully. (It is the same route as when I tracert on XP.) I have deleted the Harmony files.

I actually did a system restore on the Windows 7 box prior to the vendor being on-site and I still have the same issue. (All PLC's communicate except xxx.yyy.126.101.)

If I pull the network cable out of the 7 box and connect the XP box RSLinx on the XP can connect to all PLCs.

There are no firewalls between the PC and PLC. Any ideas of what to check next?

PING and TRACERT can be easily fooled by routers and firewalls and I don't like to rely solely on them for TCP troubleshooting.

Ideally, use TCPING [link] on TCP ports 2222 and 44818 to verify that you have TCP connectivity to all the controllers. Port 2222 will work with old PLC-5E and SLC-5/05 controllers, and Port 44818 will work with all ControlLogix and MicroLogix and newer PLC-5E an SLC-5/05 controllers.


You need to examine the subnet masks for all the hosts involve, both Windows PCs and PLC controllers.

The obvious suspect is that your Windows 7 computer is configured for a Class C subnet that excludes the ".126.101" address. Without actually seeing the numbers in your addressing scheme, I can't say if you're using a Class C or a Class B network.

That ICSA notice recommends the installation of RSLinx Classic "CPR9 SR5", which is version 2.59. If your goal is to deal with that ICSA issue, then version 2.57 is too old.

I am traveling to the plant tomorrow and I will try TCPing. I was at the site last week and I did not write down the actual subnet mask. I did check to see that they were the same between HMI.

I believe the 2.59 was what the rep installed and the plant couldn't get anything talking. That was the reason I tried to go back to 2.57, but I can't seem to get that working. We are now running on the XP machine so I really went backwards.

XP subnet was 255.255.255.0, I could TCPing xxx.yyy.126.101 on 2222 & 44818

7 subnet was 255.255.255.0, I couldn't TCPing xxx.yyy.126.101 on either port. I changed the subnet to 255.255.0.0 and now everything works. What is the difference between the XP and 7? I understand the difference in subnet masks, I just don't understand why one mask works on XP but not on 7?

Secondly, I installed 2.59. Everything is working but it seems real slow to start. The install was not real clean because I couldn't stop some of the Rockwell processes. Any insight?

Hello,
I Know this is only for answers but I do have a question about one problem I am facing, I have a PLC 1100 and one of analog is not working I bout a new one the difference is Rev d and A old one is revision a serie d and the old one is revision B and serie A, it doesn't recognized pleas help me out

@ Paiqi: Please start a new thread.