# Good OPC browse but bad tag quality **URL:** \ **Category:** Ignition\ **Tags:** ignition80\ **Created:** [January 14, 2021, 11:55pm UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276 "2021-01-14T23:55:33Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![David.Reed.Schmidt](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@David.Reed.Schmidt](https://forum.inductiveautomation.com/u/David.Reed.Schmidt)\ **Post date:** [January 14, 2021, 11:55pm UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/1 "2021-01-14T23:55:33Z")
I’m connecting to a AB Compact Logix that is a couple of PLC hops from the Ignition server. The connection path looks like this 1,2,2,1.2.35.4,1,0,2,192.168.200.80,1,0 I can browse the PLC tags in the OPC browser as in I can see all the tags. I create the OPC tag by dragging it from the OPC pallet to the Tag Pallet. The tag is made but the the tag is ‘Bad’ There are only 16 tags from this PLC that I’m interested in. I tried with a single tag from the PLC but the tag was still ‘bad’ The Ignition server version is 8.0.10 (b2020031912) Any ideas on how to fix the bad tag quality? ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 14, 2021, 11:59pm UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/2 "2021-01-14T23:59:06Z")
What driver did you use and what is the firmware version of the target PLC at the end of the path? ---
**Author:** ![David.Reed.Schmidt](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@David.Reed.Schmidt](https://forum.inductiveautomation.com/u/David.Reed.Schmidt)\ **Post date:** [January 15, 2021, 12:02am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/3 "2021-01-15T00:02:45Z")
Here is the info: Allen-Bradley Driver 5.0.10 (b2020031912) OPC-UA 8.0.10 (b2020031912) PLC: 5370 Compact Logix PLC Firmware 30.011 And I am using the Allen Bradly Logix Driver. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 15, 2021, 12:07am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/4 "2021-01-15T00:07:20Z")
Go back to a single tag and then find and turn these loggers to DEBUG and see what they’re saying: `ReadTagsRequest` `ReadArrayTagsRequest` `ReadStructuredTagsRequest` which one actually logs something will depend on the type of tag it is. ---
**Author:** ![David.Reed.Schmidt](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@David.Reed.Schmidt](https://forum.inductiveautomation.com/u/David.Reed.Schmidt)\ **Post date:** [January 15, 2021, 12:11am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/5 "2021-01-15T00:11:05Z")
> [@Kevin.Herron](#): > > `ReadTagsRequest` ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/1/9156a4dcb23c6df577f0a479876af349d3076862.png) ---
**Author:** ![David.Reed.Schmidt](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@David.Reed.Schmidt](https://forum.inductiveautomation.com/u/David.Reed.Schmidt)\ **Post date:** [January 15, 2021, 12:13am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/6 "2021-01-15T00:13:18Z")
Here it is with the trace on | ReadBrowseHashRequest | 14Jan2021 16:12:41 | | --- | --- | | | Read browse hash: LogixBrowseHash{a1=364, a2=1, a3=-21151171, a4=-103826355, a10=-1212613931} | | ReadTagsRequest | 14Jan2021 16:12:41 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:40 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:39 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | DriverAdapter | 14Jan2021 16:12:39 | | | getReferences nodeId=NodeId{ns=1, id=[RS2Bagger]Controller:Global} | | ReadTagsRequest | 14Jan2021 16:12:38 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:37 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | DriverAdapter | 14Jan2021 16:12:37 | | | getReferences nodeId=NodeId{ns=1, id=[RS2Bagger]} | | ReadBrowseHashRequest | 14Jan2021 16:12:36 | | | Read browse hash: LogixBrowseHash{a1=364, a2=1, a3=-21151171, a4=-103826355, a10=-1212613931} | | ReadTagsRequest | 14Jan2021 16:12:36 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:35 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:34 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:33 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadTagsRequest | 14Jan2021 16:12:32 | | | Error reading 1 items: status=0x01 [connection failure] , additional=[0x0318] | | ReadBrowseHashRequest | 14Jan2021 16:12:31 | | | Read browse hash: LogixBrowseHash{a1=364, a2=1, a3=-21151171, a4=-103826355, a10=-1212613931} | ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 15, 2021, 12:14am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/7 "2021-01-15T00:14:50Z")
Hmm. I don’t know why the browse would work but then when reading the device would return an error code instead. If you can get a Wireshark capture from the Ignition server where you start it, then edit/save the device in the gateway, then let at least one failed read occur, that might help. ---
**Author:** ![David.Reed.Schmidt](https://avatars.discourse-cdn.com/v4/letter/d/5f9b8f/32.png) [@David.Reed.Schmidt](https://forum.inductiveautomation.com/u/David.Reed.Schmidt)\ **Post date:** [January 15, 2021, 12:15am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/8 "2021-01-15T00:15:58Z")
I’ll get that going. Thanks for the help. More to follow tomorrow. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 15, 2021, 12:18am UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/9 "2021-01-15T00:18:38Z")
It might have something to do with CIP unconnected vs connected messaging. Browsing and that “ReadBrowseHashRequest” you’re seeing in the logs use unconnected messaging. Read and writing tag values requires using connected messaging, which requires that a logical CIP connection be established via the ForwardOpen service. You have 3 different PLCs involved here - if any of these are unable to establish a connection to the next or have a connection opened, e.g. because it’s already got too many connections to it, that might explain what you’re seeing. ---
**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:** [January 15, 2021, 2:02pm UTC](https://forum.inductiveautomation.com/t/good-opc-browse-but-bad-tag-quality/42276/10 "2021-01-15T14:02:41Z")
> [@Kevin.Herron](#): > > because it’s already got too many connections to it I would check this part out--all but the very latest Logix processors have strict limits on total connection counts. And chassis-based network devices (ENBT, etc) also have connection limits. This document has more information in Chapter 3: > **[1756-rm094\_-en-p.pdf](https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm094_-en-p.pdf)** > > 4.83 MB Logix 5580 and 5480 processors have communications coprocessors that apparently lift these limits for their built-in ports.