# Cannot establish communication to Controllogix **URL:** \ **Category:** Ignition\ **Created:** [April 2, 2013, 10:19am UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134 "2013-04-02T10:19:01Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Brett\_Yeomans](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Brett\_Yeomans](https://forum.inductiveautomation.com/u/Brett_Yeomans)\ **Post date:** [April 2, 2013, 10:19am UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/1 "2013-04-02T10:19:01Z")
Hi, I am trying to connect to a Contrologix via the DHRIO solution and cannot achieve this. I have set up a test rig identical to the diagram in the Ignition manual but all I get is: Disconnect EIP Protocul Unknown My Connection path is 1,3,2,12,1,0 the DHRIO in the gateway is slot 3 CHA going to node 12 with CPU in slot 0. This fails on plant where the same DH+ network is picking up a handful of SLC’s on it but not the Controllogix trying to use the connection path. Where do I go from here? I am using ver 7.5.6 ---
**Author:** ![Travis.Cox](https://avatars.discourse-cdn.com/v4/letter/t/b9bd4f/32.png) [@Travis.Cox](https://forum.inductiveautomation.com/u/Travis.Cox)\ **Post date:** [April 2, 2013, 3:31pm UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/2 "2013-04-02T15:31:51Z")
The DH+ station number needs to be octal. If you are specifying 12 in decimal it should be 14 in octal. ---
**Author:** ![Brett\_Yeomans](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Brett\_Yeomans](https://forum.inductiveautomation.com/u/Brett_Yeomans)\ **Post date:** [April 3, 2013, 7:10am UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/3 "2013-04-03T07:10:25Z")
Tried that and still says disconnected. Below is the RSLinx screenshot of the setup. I cannot connect to two seperate Controllogix’s via this method so I’m doing something wrong ![:scratch:](https://us1.discourse-cdn.com/inductiveautomation/original/1X/76d1620bec252bfac07050c889ff5a91dc8a9c25.gif ":scratch:") If I take the CPU out of the second rack and place it in the first rack, delete the connection path and assign the slot number then Ignition connects. For some reason it will not connect over the DHRIO. ![]() ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/d/de20458cab69b12e7724eb83ba3addd718858e77.JPG) ---
**Author:** ![thechtman](https://avatars.discourse-cdn.com/v4/letter/t/e56c9b/32.png) [@thechtman](https://forum.inductiveautomation.com/u/thechtman)\ **Post date:** [April 5, 2013, 2:59pm UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/4 "2013-04-05T14:59:53Z")
If RSLinx is showing DH+ station 12 which is octal, then you should use 10 decimal. So your connection path will be 1,3,2,10,1,0. ---
**Author:** ![Travis.Cox](https://avatars.discourse-cdn.com/v4/letter/t/b9bd4f/32.png) [@Travis.Cox](https://forum.inductiveautomation.com/u/Travis.Cox)\ **Post date:** [April 5, 2013, 4:10pm UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/5 "2013-04-05T16:10:07Z")
Thanks Tom. I was backwards on my post. ---
**Author:** ![Brett\_Yeomans](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Brett\_Yeomans](https://forum.inductiveautomation.com/u/Brett_Yeomans)\ **Post date:** [April 8, 2013, 8:01am UTC](https://forum.inductiveautomation.com/t/cannot-establish-communication-to-controllogix/6134/6 "2013-04-08T08:01:43Z")
Thanks that sorted it. ![:thumb_left:](https://us1.discourse-cdn.com/inductiveautomation/original/1X/e26afb081ddde6df016df6ee49159cf56aaca688.gif ":thumb\_left:") Just re-read the Allen Bradley Drivers section of the manual and every example mentions the station is in Octal (although every example is geared at PLC5 or SLC) even the Controllogix connection diagram just says ‘DH+ station number’. Might want to highlight this in the connection guide.