# User defined modbus read HR request

**URL:** <https://forum.inductiveautomation.com/t/user-defined-modbus-read-hr-request/35816>\
**Category:** Ignition\
**Created:** [June 19, 2020, 6:16am UTC](https://forum.inductiveautomation.com/t/user-defined-modbus-read-hr-request/35816 "2020-06-19T06:16:04Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jeff.li](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jeff.li/32/68813_2.png) [@jeff.li](https://forum.inductiveautomation.com/u/jeff.li)\
**Post date:** [June 19, 2020, 6:16am UTC](https://forum.inductiveautomation.com/t/user-defined-modbus-read-hr-request/35816/1 "2020-06-19T06:16:04Z")

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Hi, Dears,

I have one modbus device which connect to Igniton by modbus RTU over TCP, now connection is ok, but when I want to read the HR area, this device requires a special request, actually I don’t know exactly which kind of request will be sent from Ignition side automatically.

for my device, the address are in x16, so for example, if I want get data from address A20H-A30H, 1st I need send request 00 03 A0 20 00 11 A7 DD (x16 also) then I will get the result from the device, by the way is a singal chip machine, and Ignition version is 8.0.13, so is it possible to edit read HR request and send it to the device?

thanks a lot!