Start in three steps
Read voltage from a virtual Siglent SDM3055 multimeter and check how your SCPI client handles command replies.
Before you start: Install SPX with ASCII/SCPI support and SPX UI. Have a raw TCP client ready. Download the SDM3055 model.
1. Create a virtual multimeter
Import the YAML in Models → Load model from file. In Instances → New instance, select your registered model and set ascii_port to 5025. Choose Create, then Start instance. Confirm RUNNING. Port 5025 is this exercise’s override; the model default 0 requests an allocated port.
2. Connect and identify the instrument
Open Communication → ascii and connect your client to the reachable SPX host and published TCP port. Send *IDN? followed by LF (\n). Read through the next LF. Expect SIGLENT,SDM3055,SDM3055S0000000,1.01.
3. Read and change a measurement
Send MEAS:VOLT:DC? followed by LF. Success: the default reply represents 1.234 V. In SPX Attributes, set voltage_dc_v to 2.5, query again and verify 2.5 V. Restore 1.234, then choose Stop instance.
Protocol communication
Use these settings and messages with the library’s Siglent SDM3055 multimeter model.
- Client / transport
- Raw TCP socket → SPX_HOST:5025; Communication → ascii
- Framing
- ASCII commands; terminate with LF (\n); read replies through LF
- Docker
- Publish the chosen TCP port; 5025 is this exercise’s override
Replace host placeholders with reachable addresses and use your published ports.
Swipe the table to see requests and replies.
| Address / message | Operation / payload | Expected reply |
|---|---|---|
*IDN? | Query identity | SIGLENT,SDM3055,SDM3055S0000000,1.01 |
MEAS:VOLT:DC? | Query DC voltage | 1.234 at model defaults, in V |
MEAS:CURR:DC? | Query DC current | 0.123 at model defaults, in A |
CONF:CURR:DC | Select current measurement | No reply; follow with READ? after the next simulation update |
READ? | Query the selected measurement | 0.123 after selecting current; 1.234 in default voltage mode |
SYST:ERR? | Query error status | 0,No error at model defaults |
Values describe this model’s nominal setup unless noted. Live measurements change as the simulation runs.
Example request and reply
Send *IDN? followed by LF and verify the identity. Query MEAS:VOLT:DC?, change voltage_dc_v in SPX Attributes, then query again to verify the new value.
Send: *IDN?\n
Recv: SIGLENT,SDM3055,SDM3055S0000000,1.01\n
Send: MEAS:VOLT:DC?\n
Recv: 1.234\n
Send: CONF:CURR:DC\n (no reply; wait for a simulation update)
Send: READ?\n
Recv: 0.123\nNo reply or an unexpected value?
- Use raw TCP, not HTTP. Missing LF leaves the command buffered without a reply.
- Read a reply only for queries. This model’s configuration commands are silent; waiting for a response after CONF:CURR:DC will time out.
- Use the exact command spellings listed here. This compact model does not implement every instrument command or long-form SCPI alias.
What you can test next
- Select current mode with
CONF:CURR:DC, then queryREAD?after a simulation update. - Query
SYST:ERR?and compare the result with the command map. - Use the linked model to check which exact command spellings are implemented.
See the SCPI adapter guide for configuration details.