# Does NetSenX record the values written to our controllers?

No. NetSenX records that a write happened, from which host, to which controller, with the function code and the time, but not the value written or the contents of a program block. That is a deliberate limit: process values and programs are your know-how, and an alert needs the who and when, not the recipe. If you need the values, for example to reconstruct a bad batch, they come from the historian, the SCADA or HMI audit trail or the controller's own diagnostics. Plan for this before you need it: check how long your historian keeps data and whether HMI changes are logged with a user name. NetSenX reads Modbus/TCP, DNP3, BACnet/IP, EtherNet/IP and S7comm from passive capture, from the Pro plan, and never sends anything to the devices.

FAQ: [OT and IoT](https://netsenx.com/en/faq/ot) · https://netsenx.com/en/faq/does-netsenx-record-the-values-written-to-controllers

## Read next

- https://netsenx.com/en/ot-network-monitoring
- https://netsenx.com/en/compare

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