# Need help with tags from PAC4200 (modbus TCP) **URL:** \ **Category:** Ignition\ **Created:** [November 23, 2015, 12:56pm UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816 "2015-11-23T12:56:01Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![ATech](https://avatars.discourse-cdn.com/v4/letter/a/a88e4f/32.png) [@ATech](https://forum.inductiveautomation.com/u/ATech)\ **Post date:** [November 23, 2015, 12:56pm UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/1 "2015-11-23T12:56:01Z")
Similar problem described (with Siemens PAC3200 power monitor) here: [inductiveautomation.com/forum/v … 97b#p35869](https://inductiveautomation.com/forum/viewtopic.php?f=72&t=10158&p=35869&hilit=pac3200&sid=98c149a3ed98aa8efd22880afb0d197b#p35869) I have PAC4200 configured in gateway (says that the device is connected). Tried different ways, but all I get is a tag with unknown quality and NULL value. Can someone give advice how to read tags from PAC4200 using Modbus TCP driver? Thank you! Anatoly ---
**Author:** ![Josh1](https://avatars.discourse-cdn.com/v4/letter/j/71c47a/32.png) [@Josh1](https://forum.inductiveautomation.com/u/Josh1)\ **Post date:** [November 22, 2016, 12:09am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/2 "2016-11-22T00:09:31Z")
Did you ever find a solution? I have the same exact problem that you had. Thanks! EDIT: Never mind, I was able to get it communicating. I had to address the last register number of each register that I wanted to read from. ---
**Author:** ![ena\_bj](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/ena_bj/32/13318_2.png) [@ena\_bj](https://forum.inductiveautomation.com/u/ena_bj)\ **Post date:** [December 1, 2016, 11:51am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/3 "2016-12-01T11:51:24Z")
[quote=“Josh@BC”]Did you ever find a solution? I have the same exact problem that you had. Thanks! EDIT: Never mind, I was able to get it communicating. I had to address the last register number of each register that I wanted to read from.[/quote] I also have the problem. Can you clarify your solution? ---
**Author:** ![greg.simpson](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/greg.simpson/32/3135_2.png) [@greg.simpson](https://forum.inductiveautomation.com/u/greg.simpson)\ **Post date:** [December 13, 2016, 12:17am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/4 "2016-12-13T00:17:32Z")
If you have a map of the registers you need to subscribe to you can follow the videos on Inductive University linked here [inductiveuniversity.com/video/a … /?q=modbus](https://inductiveuniversity.com/video/about-modbus-addressing?r=/video/search/?q=modbus) You can also reference the user manual, here [docs.inductiveautomation.com/di … Addressing](https://docs.inductiveautomation.com/display/DOC79/Modbus+Addressing) ---
**Author:** ![chi](https://avatars.discourse-cdn.com/v4/letter/c/0ea827/32.png) [@chi](https://forum.inductiveautomation.com/u/chi)\ **Post date:** [December 13, 2016, 8:06am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/5 "2016-12-13T08:06:51Z")
I am using some PAC3200 with the Ignition OPC-UA server without problems. There is a little trick with the modbus address, you have to set a device address unlike 0 `[PAC3200]1.HRF65` Offset 65 is the current active power in the 3200 (should be the same in the 4200 according to the manual). There are two weak points of the Ignition Modbus UA Server: - missing support for 64bit values (4 consecutive Modbus registers) - no ‘write only’ mode. The PAC errors out when the Modbus client tries to read one of the write only registers. I made a UDT that handles this points in python scripts. ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [November 21, 2017, 4:53pm UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/6 "2017-11-21T16:53:21Z")
Split this topic on November 21, 2017, 4:53pm UTC A post was split to a new topic: [Problems with Modbus device](https://forum.inductiveautomation.com/t/problems-with-modbus-device/16076) ---
**Author:** ![maniaero14](https://avatars.discourse-cdn.com/v4/letter/m/ad7895/32.png) [@maniaero14](https://forum.inductiveautomation.com/u/maniaero14)\ **Post date:** [November 23, 2017, 9:51am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/7 "2017-11-23T09:51:33Z")
I have PAC3200 configured webpage device will be connected. but I get tag value is unknown quality and NULL value. Can someone help me how to read tags from PAC3200 using Modbus TCP driver? ---
**Author:** ![jferizag](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@jferizag](https://forum.inductiveautomation.com/u/jferizag)\ **Post date:** [October 11, 2018, 4:23am UTC](https://forum.inductiveautomation.com/t/need-help-with-tags-from-pac4200-modbus-tcp/10816/8 "2018-10-11T04:23:44Z")
Did you ever find a solution? can you help in these topic? I need urgent. what is the syn please. My E-mail is: [jferizag@yahoo.com](mailto:jferizag@yahoo.com) thanks you.