# CompactLogix V20 Long String tag **URL:** \ **Category:** Ignition\ **Created:** [June 16, 2022, 7:17pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854 "2022-06-16T19:17:45Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![gregory.sachs](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@gregory.sachs](https://forum.inductiveautomation.com/u/gregory.sachs)\ **Post date:** [June 16, 2022, 7:17pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/1 "2022-06-16T19:17:45Z")
I’ve got a gateway running 7.9.20. I’m talking to a CompactLogix V20 PLC, and when i try to access a long string tag of ~400 characters, it appears as a DATA folder with individual character elements. Is there a solution to this to access as a string? I"m using the legacy driver, this happens with both 20.012 and 20.013 PLC firmware. I’m leaning towards installing rslinx gateway to use as the OPC server, but curious if there is a native solution (aside from get rid of the antique hardware) I’ve seen the ideas of building a list and doing a bidirectional derived tag. Thanks! ---
**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:** [June 16, 2022, 7:27pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/2 "2022-06-16T19:27:01Z")
Aside from the derived tag idea, you could try using the v21+ driver only for this large String tag. I know that large strings can be read/written in 8.1, I think that’s also true in 7.9 (though I wouldn’t be surprised if it turned out you can only read them). ---
**Author:** ![gregory.sachs](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@gregory.sachs](https://forum.inductiveautomation.com/u/gregory.sachs)\ **Post date:** [June 16, 2022, 7:29pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/3 "2022-06-16T19:29:15Z")
Sorry, that rung a bell. I believe I tried the non-legacy driver, and you are correct, it would read but not write. Is the 8.1 driver different and likely to work for read/write? ---
**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:** [June 16, 2022, 7:30pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/4 "2022-06-16T19:30:16Z")
> [@gregory.sachs](#): > > Is the 8.1 driver different and likely to work for read/write? It's just different in that at some point we fixed writing to large strings, but I thought it was only broken for strings that were large enough to require multiple requests (larger than the CIP connection size, minus some overhead), and a 400 byte string should fit. You can't use the 8.x driver in a 7.9 gateway though. ---
**Author:** ![gregory.sachs](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@gregory.sachs](https://forum.inductiveautomation.com/u/gregory.sachs)\ **Post date:** [June 16, 2022, 8:36pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/5 "2022-06-16T20:36:57Z")
No, but i can stand up a 8.1 test bed and try to upgrade the project to see if that fixes. ---
**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:** [June 16, 2022, 9:19pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/6 "2022-06-16T21:19:04Z")
Not a bad idea to explore upgrading anyway. 7.9 EOL is in 2 weeks, and that’s after already being extended 6 months. It was originally going to be EOL at the start of the year. ---
**Author:** ![gregory.sachs](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@gregory.sachs](https://forum.inductiveautomation.com/u/gregory.sachs)\ **Post date:** [June 17, 2022, 3:13pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/7 "2022-06-17T15:13:54Z")
Roger that. On the upgrade guide, it might be useful to add an explicit note that system.tag.write will still work, it is a little unclear. Regarding my issue, I installed a 7.9.20 test bed, restored a backup from my production server, and then upgraded to 8.1.17. After doing that; I am connected to a single PLC using both the legacy driver and the modern driver. Using the legacy driver, all tags showed as bad. Very possible this is a PLC issue, it is an old Compact and I’ve got 2x igniton servers and a FTTM connection. The modern driver was able to read/write my long strings, so that seems positive. ---
**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:** [June 17, 2022, 4:00pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/8 "2022-06-17T16:00:34Z")
I just want to clarify that when I said only use the v21 driver for the String tags I meant that. When connected to an older processor the driver has to use symbolic addressing, which is _very_ slow, and you will get absolutely crap performance if you try to get all your tags from this PLC using the v21 driver. ---
**Author:** ![gregsachs](https://avatars.discourse-cdn.com/v4/letter/g/58f4c7/32.png) [@gregsachs](https://forum.inductiveautomation.com/u/gregsachs)\ **Post date:** [June 20, 2022, 4:42pm UTC](https://forum.inductiveautomation.com/t/compactlogix-v20-long-string-tag/60854/9 "2022-06-20T16:42:29Z")
Roger, thanks-I think I’m going to “solve” by just using RsLinx Gateway, I have a spare license that I can deploy.