# Can not connect to DH485 **URL:** \ **Category:** Ignition\ **Tags:** troubleshooting\ **Created:** [April 2, 2024, 5:16pm UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251 "2024-04-02T17:16:52Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![kevin\_wadiak](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kevin\_wadiak](https://forum.inductiveautomation.com/u/kevin_wadiak)\ **Post date:** [April 2, 2024, 5:16pm UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/1 "2024-04-02T17:16:52Z")
Can someone help me connect to a PLC SLC 5/02 Processor through an IP address and a DHRIO card then DH485 This is for a OPC/UA topic ![ighel](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/b/9b8221a1139070060ff7e07fa28a5c28ab9abe10.jpeg) ---
**Author:** ![Cory.grube](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cory.grube/32/20476_2.png) [@Cory.grube](https://forum.inductiveautomation.com/u/Cory.grube)\ **Post date:** [April 2, 2024, 6:30pm UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/2 "2024-04-02T18:30:54Z")
You'll need to use [connection paths](https://docs.inductiveautomation.com/docs/8.1/ignition-modules/opc-ua/opc-ua-drivers/allen-bradley-ethernet/allen-bradley-connection-paths#connecting-to-multiple-slcs-using-data-highway-plus-dh) in your device connection to talk over the DH485 card. The example in the docs is specifically SLC over DH+, conveniently! Using that guide, looks like your connection path should be 1,2,2,8. As far as I know, Ignition follows all the same rules as CIP routing in Logix. ---
**Author:** ![kevin\_wadiak](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kevin\_wadiak](https://forum.inductiveautomation.com/u/kevin_wadiak)\ **Post date:** [April 2, 2024, 6:45pm UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/3 "2024-04-02T18:45:01Z")
Thank you, I Did try that 1,2,2,8 from the video. This is DH485 I believe and not Plus if that matters this is what it says ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/7/07ec7028727c59daee913715ee557aa5137cfa0b.png) ---
**Author:** ![Cory.grube](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cory.grube/32/20476_2.png) [@Cory.grube](https://forum.inductiveautomation.com/u/Cory.grube)\ **Post date:** [April 2, 2024, 6:58pm UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/4 "2024-04-02T18:58:40Z")
I checked on Rockwell's Knowledgebase (Answer ID [BF5708](https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1066637) - TechConnect required). Both DHRIO and DH-485 use `2` for Channel A and `3` for Channel B. Out of curiosity, can you connect to any other PLCs on either the DH+/DHRIO bus? * * * I did just notice this though, this is probably your issue: > [Supported SLC Connection Methods](https://docs.inductiveautomation.com/docs/8.1/ignition-modules/opc-ua/opc-ua-drivers/allen-bradley-ethernet/connecting-to-slc#supported-slc-connection-methods) > > - SLC505 direct > - SLC505, SLC504, SLC503 connected through 1761-NET-ENI > - SLC504 connected through 1756-DHRIO > - SLC505, SLC504, SLC503 connected through Spectrum Controls WebPort 500 No mention of the 1756-DH485 card you're using. Or SLC 501/502 at all, for that matter. ---
**Author:** ![kevin\_wadiak](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kevin\_wadiak](https://forum.inductiveautomation.com/u/kevin_wadiak)\ **Post date:** [April 3, 2024, 10:23am UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/5 "2024-04-03T10:23:52Z")
Thank you for taking the time to reply, yes the ones highlighted I am able to connect and read tags. I just cannot connect to the circled PLC. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/9/491f3027a6b4c464e2d966a1b6cfd745bd228eed.png) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [April 3, 2024, 11:08am UTC](https://forum.inductiveautomation.com/t/can-not-connect-to-dh485/88251/6 "2024-04-03T11:08:42Z")
Right, the highlighted ones are ethernet and DH+. Ignition's docs don't show any support for DH485.