# Modbus Read Timeout

**URL:** <https://forum.inductiveautomation.com/t/modbus-read-timeout/87439>\
**Category:** Ignition\
**Created:** [March 17, 2024, 3:28am UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439 "2024-03-17T03:28:35Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![jrankin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jrankin/32/17076_2.png) [@jrankin](https://forum.inductiveautomation.com/u/jrankin)\
**Post date:** [March 17, 2024, 3:28am UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439/1 "2024-03-17T03:28:35Z")

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![Modbus_error_p1](https://us1.discourse-cdn.com/inductiveautomation/original/3X/0/9/0961f325e5ed96ab80340451a77d4915be0da28f.png)  
 ![Modbus_error_p2](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/4/e4e557087bad72c37c7d58bed879e65031e065d1.png)  
 ![Modbus_error_p3](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/f/dfb3c221728228cd0d84799f24e43bada2838f4c.png)

Hello,

Having a Modbus read error issue. Using a flow meter connected to a CommField RS485 to Modbus TCP converter. DVS-485-2.

I may have the incorrect addresses, but would that prevent a response?

Inbound and Outbound port 502 open.

Any help would be appreciated.

Thanks!

Jeff

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**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:** [March 17, 2024, 11:48am UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439/2 "2024-03-17T11:48:57Z")

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> [@jrankin](#):
>
> I may have the incorrect addresses, but would that prevent a response?

Often, yes.

Try unit ID 1 instead of 0.

I'd also recommend you don't use the address mapping at all; just create OPC tags using the address syntax outlined in the manual.

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**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:** [March 17, 2024, 12:32pm UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439/3 "2024-03-17T12:32:04Z")

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Your screenshot clearly identifies this as a core certification test. Getting help for such on the forum is forbidden.

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<div class="post-metadata">

**Author:** ![jrankin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jrankin/32/17076_2.png) [@jrankin](https://forum.inductiveautomation.com/u/jrankin)\
**Post date:** [March 17, 2024, 4:09pm UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439/4 "2024-03-17T16:09:56Z")

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Already turned my test. This is for an unrelated problem. But I appreciate the concern! I'll change the name of the Gateway : )

Jeff

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<div class="post-metadata">

**Author:** ![jrankin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jrankin/32/17076_2.png) [@jrankin](https://forum.inductiveautomation.com/u/jrankin)\
**Post date:** [March 18, 2024, 12:08am UTC](https://forum.inductiveautomation.com/t/modbus-read-timeout/87439/5 "2024-03-18T00:08:17Z")

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I'll be remoting in on system that my questions are based on soon. I'll try your suggestions. Thanks!