# DNP3 Legacy Driver BO command type

**URL:** <https://forum.inductiveautomation.com/t/dnp3-legacy-driver-bo-command-type/111564>\
**Category:** Ignition\
**Created:** [October 17, 2025, 5:58pm UTC](https://forum.inductiveautomation.com/t/dnp3-legacy-driver-bo-command-type/111564 "2025-10-17T17:58:39Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Soham\_Chakrabarti](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Soham\_Chakrabarti](https://forum.inductiveautomation.com/u/Soham_Chakrabarti)\
**Post date:** [October 17, 2025, 5:58pm UTC](https://forum.inductiveautomation.com/t/dnp3-legacy-driver-bo-command-type/111564/1 "2025-10-17T17:58:39Z")

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I am using DNP3 Legacy driver to connect to an RTAC. I am controlling some breakers using Binary Outputs, one is for tripping and the other to close in. The open button writes True to the BO tag setup to open and vice versa.

When I trigger the BOs from Ignition, I don’t see any change in either operPulse, operLatchOn, operLatchOff, operTrip or operClose in the RTAC. If Ignition pulses the BOs, maybe I can see it change as it is very fast. But can anyone confirm how BOs work with DNP3 legacy driver? Thanks

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**Author:** ![Cody\_Morgan](https://avatars.discourse-cdn.com/v4/letter/c/db5fbb/32.png) [@Cody\_Morgan](https://forum.inductiveautomation.com/u/Cody_Morgan)\
**Post date:** [October 21, 2025, 8:57pm UTC](https://forum.inductiveautomation.com/t/dnp3-legacy-driver-bo-command-type/111564/2 "2025-10-21T20:57:46Z")

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If I understand correctly, when using the legacy driver, if you write `True` to a BinaryOutput tag, the driver should send this request to the outstation:

Group: 12  
Variation: 1  
Index: {indicatedByTag}  
Control code: 3 (Op: LATCH\_ON, TCC: NUL, CR: 0)  
Count: 1  
On Time: 0  
Off Time: 0  
Status Code: 0

If you write `False`, then you should see the same except Control code 4 (`LATCH_OFF`) is used instead. You should be able to verify this with wireshark.

You may want to try using the scripting functions in `system.dnp3`. They give you more control over the control code, onTime, and offTime parameters. Depending on your outstation's output model, it may activate too quickly or do nothing at all when onTime is set to 0. Additionally, make sure that controls are enabled in your RTAC config.