# Modbus Communication to Hach SC1000 Device

**URL:** <https://forum.inductiveautomation.com/t/modbus-communication-to-hach-sc1000-device/69942>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [February 16, 2023, 3:42pm UTC](https://forum.inductiveautomation.com/t/modbus-communication-to-hach-sc1000-device/69942 "2023-02-16T15:42:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![valverde.anthony](https://avatars.discourse-cdn.com/v4/letter/v/278dde/32.png) [@valverde.anthony](https://forum.inductiveautomation.com/u/valverde.anthony)\
**Post date:** [February 16, 2023, 3:42pm UTC](https://forum.inductiveautomation.com/t/modbus-communication-to-hach-sc1000-device/69942/1 "2023-02-16T15:42:12Z")

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Hello,

I am attempting to connect to a Hach SC1000 controller. I am seeing a Connected Status from the device connections, however, I am receiving a

`Received response with ExceptionCode: 0x04 (SlaveDeviceFailure).`

I've attempted enable/disable span gaps, I've reviewed the address input into the OPC Item Path = {device\_name}{unit\_id}.HRF{float\_holding\_register}. Has anyone successfully connected to a Hach SC1000 controller previously and ran into similar issues?

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<div class="post-metadata">

**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:** [February 16, 2023, 3:51pm UTC](https://forum.inductiveautomation.com/t/modbus-communication-to-hach-sc1000-device/69942/2 "2023-02-16T15:51:04Z")

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Have you tried other datatypes? (On 16-bit registers?) Can you get a wireshark capture of what's happening? Can you get a wireshark capture of successful communications with a generic Modbus query tool?