Verify an instrument LAN connection with Telnet

The fastest possible sanity check: ping the instrument, open a Telnet session to the SCPI port, and type *IDN? by hand.

5 min readIncludes code

When remote control misbehaves, test the layers in order: cable → IP → SCPI. Telnet gives you a live keyboard session straight into the instrument's SCPI parser, so you can prove the network path with zero code.

Step 1 — Ping the instrument

bash

ping 192.168.1.121

What you should see

Reply from 192.168.1.121: bytes=32 time=1ms TTL=64

No reply? Fix this first: check the cable/link LEDs, confirm the instrument's IP settings (DHCP vs static) in its LAN/IO menu, and make sure PC and instrument share the same subnet.

Step 2 — Open a Telnet session to port 5024

Windows: enable the Telnet client once via Turn Windows features on or off, or use PuTTY (see the related note). Then:

bash

telnet 192.168.1.121 5024

Port 5024 is the interactive Telnet service (it echoes a welcome banner and prompt on supporting models); port 5025 is the raw SCPI socket — you can Telnet to either.

Step 3 — Type a query

scpi

*IDN?

What you should see

Siglent Technologies,SSA3032X Plus,SSA3PBC1R0001,3.2.2.2.0

A full identification string proves cabling, IP configuration and the SCPI service in one shot. If Telnet works but your program doesn't, the problem is in your code or VISA layer — not the network.

Instruments used in this note

Any Siglent LAN instrument

Telnet (5024) and raw SCPI (5025) services

View

Related application notes

Test SCPI socket communications with PuTTY Verify a remote connection with NI-MAX Open-socket LAN control with Python (port 5025)

Questions about this measurement?

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