# Cannot get modbus float tag to display correctly **URL:** \ **Category:** Ignition\ **Created:** [July 28, 2017, 6:59pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924 "2017-07-28T18:59:52Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![jeff.crockett99](https://avatars.discourse-cdn.com/v4/letter/j/43a26b/32.png) [@jeff.crockett99](https://forum.inductiveautomation.com/u/jeff.crockett99)\ **Post date:** [July 28, 2017, 6:59pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/1 "2017-07-28T18:59:52Z")
I am having on heck of a time trying to get my float tag in ignition to display the correct value from the PLC I’m using. I’m using a ClickPLC, which is modbus TCP. These are my tag properties: Data Type: Float Enabled: Yes Access Rights: Read Only OPC Server: Ignition OPC-UA Server OPC Path: [MyDevicesName]HRF28673 Source Data Type: Automatic I’m 95% sure I have my modbus address correct for the address I’m trying to read. My PLC tells me that the modbus address is 428673 with Function Code 03,06,16. From what I understand, I need to disregard the first 4 in the address, which I have. With this current setup, I am seeing my tag value in ignition change in real time as I adjust my 0-10v signal to the plc. However, it is showing all sorts of funky values. It will jump from 0, to extremely large numbers in the billions, to negative billions numbers, etc. I have tried scaling with the highest and lowest integer values that my PLC will display, but still no luck. I don’t understand, especially since the values in my PLC are displaying just fine. Any help on this would be great! 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:** [July 28, 2017, 7:02pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/2 "2017-07-28T19:02:17Z")
Have you tried toggling the one-based addressing setting yet? (or just addressing +/- 1 from 28673) ---
**Author:** ![jeff.crockett99](https://avatars.discourse-cdn.com/v4/letter/j/43a26b/32.png) [@jeff.crockett99](https://forum.inductiveautomation.com/u/jeff.crockett99)\ **Post date:** [July 28, 2017, 7:03pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/3 "2017-07-28T19:03:14Z")
I have not, where is this setting located? ---
**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:** [July 28, 2017, 7:03pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/4 "2017-07-28T19:03:52Z")
It’s a setting on the device you set up in the Ignition gateway. ---
**Author:** ![jeff.crockett99](https://avatars.discourse-cdn.com/v4/letter/j/43a26b/32.png) [@jeff.crockett99](https://forum.inductiveautomation.com/u/jeff.crockett99)\ **Post date:** [July 28, 2017, 7:04pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/5 "2017-07-28T19:04:14Z")
Hmmm, I’ll check that out. Thanks ---
**Author:** ![jeff.crockett99](https://avatars.discourse-cdn.com/v4/letter/j/43a26b/32.png) [@jeff.crockett99](https://forum.inductiveautomation.com/u/jeff.crockett99)\ **Post date:** [July 28, 2017, 7:08pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/6 "2017-07-28T19:08:12Z")
Wow, what the hell. That worked. Mind giving my a really brief explanation as to why that worked? ---
**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:** [July 28, 2017, 7:17pm UTC](https://forum.inductiveautomation.com/t/cannot-get-modbus-float-tag-to-display-correctly/14924/7 "2017-07-28T19:17:01Z")
Some manufacturers specify Modbus addresses as if the base address is 0, some specify it as if it were 1. The driver defaults to treating 1 as the base because that’s how the Modbus specification describes them… in the abstract. The confusion arises because on the wire they are addressed starting at 0.