# WHATPORT(1090)

## NAME

port 1090 — FOUNDATION Fieldbus HSE — FMS — The Fieldbus Message Specification port — the actual read/write messaging of FOUNDATION Fieldbus HSE.

Protocol: TCP  
IANA registry

## DESCRIPTION

FMS is the application-layer messaging service of FOUNDATION Fieldbus: it is how a host reads and writes the parameters of function blocks living in field devices. On HSE it is registered to the Fieldbus Foundation on port 1090, alongside annunciation on 1089 and system management on 1091. If 1090 is open, you are looking at process-control gear — a linking device, gateway, or controller — not an office server.

## EXPOSURE

**Do not expose.** FMS is the write path into live process control. Anything that can reach it can attempt to change device parameters; isolate it on the control network.

## CHECK

```sh
nmap -sV -Pn -p 1090 TARGET
```

## SEE ALSO

- iana — [IANA port registry — 1090 (ff-fms)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1090) (iana.org)
- source — [ITI/ICS-Security-Tools — ICS protocol port list (FOUNDATION Fieldbus HSE, 1089-1091)](https://github.com/ITI/ICS-Security-Tools/blob/master/protocols/PORTS.md) (github.com)

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HTML: <https://whatport.net/1090/> · JSON: <https://whatport.net/1090.json> · full dataset: <https://whatport.net/ports.json>