# Can NetSenX block a dangerous command to a PLC?

No. NetSenX listens to a copy of the traffic and informs your engineers; it does not sit in the path, so it cannot drop a packet, and it never acts on the process. That is intentional: an inline device that blocks industrial commands can stop a line by mistake, and NetSenX is not a safety system. Protection against dangerous commands comes from other layers: a firewall between zones that allows only named hosts, write protection and key switches on the controllers, and a safety instrumented system that does not depend on the control network. What NetSenX adds, from the Pro plan, is the alert when a host that should not write does, when a controller receives an S7comm command such as a stop, or when OT traffic appears at night, so that someone can check before the next shift starts.

FAQ: [OT and IoT](https://netsenx.com/en/faq/ot) · https://netsenx.com/en/faq/can-netsenx-block-a-dangerous-command-to-a-plc

## Read next

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

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