Connecting your software

Each instrument on the bench is a TCP socket on 127.0.0.1, on its own port. For VISA, the resource is:

TCPIP0::127.0.0.1::<port>::SOCKET

Termination: messages end with a newline (\n, 0x0A) in both directions. With ::SOCKET resources VISA does not add it by default: set it on your session, or your software will wait for an answer that Crucible does not process until it receives the newline.

PyVISA

pip install pyvisa pyvisa-py is enough; NI-VISA is not needed. This script talks to the supply and the multimeter on the example bench:

import pyvisa

rm = pyvisa.ResourceManager("@py")  # o ResourceManager() si usas NI-VISA
opciones = dict(read_termination="\n", write_termination="\n")

fuente = rm.open_resource("TCPIP0::127.0.0.1::5025::SOCKET", **opciones)
dmm = rm.open_resource("TCPIP0::127.0.0.1::5026::SOCKET", **opciones)

print(fuente.query("*IDN?"))
fuente.write("VOLT 5")
fuente.write("OUTP ON")
print(fuente.query("MEAS:CURR?"))  # 5 V sobre la carga de 10 ohmios
print(dmm.query("MEAS:VOLT?"))

$ python3 conectar.py
Crucible,FUENTE-DC,SIM0001,1.0
0.50001
+3.300139E+00

The supply has a simulated 10 Ω load connected, so at 5 V it gives half an ampere. The multimeter reads 3.3 V because the example bench sets that when it starts (chapter 5). The last digit is Gaussian noise, which repeats the same every time you start the bench (chapter 7).

NI MAX and LabVIEW

Not verified in this manual.

Add the instrument in NI MAX as VISA TCP/IP Resource → Manual Entry of Raw Socket, with host 127.0.0.1 and the bench port. In LabVIEW, when opening the VISA session, enable the \n (0x0A) termination character for reads (Termination Character Enabled) and end every write with \n.

Windows, without installing anything

From PowerShell. It is the same test continuous integration runs against the Windows installer on every release:

$c = New-Object Net.Sockets.TcpClient('127.0.0.1', 5025); $s = $c.GetStream()
$w = New-Object IO.StreamWriter($s); $w.AutoFlush = $true; $w.WriteLine('*IDN?')
(New-Object IO.StreamReader($s)).ReadLine(); $c.Close()

If your software points at the real bench’s IPs

Software that today opens TCPIP0::192.168.1.10::5025::SOCKET, TCPIP0::192.168.1.11::5025::SOCKET… has to open TCPIP0::127.0.0.1::5025::SOCKET, TCPIP0::127.0.0.1::5026::SOCKET… Change the addresses in its configuration; you choose the ports in banco.yaml.

If it uses ::INSTR (VXI-11) resources, you can keep them: declare the vxi11 transport in the bench (see below) or, if you would rather keep things simple, change them to ::SOCKET.

VXI-11 (::INSTR)

If your software cannot change resource strings, set tipo: vxi11 in the transport and give each instrument its own IP, like the real bench:

- id: generador
  perfil: perfiles/n5171b.yaml
  transporte: { tipo: vxi11, host: 127.0.0.2, puerto: 5025, device: inst0 }

- id: fuente
  perfil: perfiles/n5767a.yaml
  transporte: { tipo: vxi11, host: 127.0.0.3, puerto: 5025, device: inst0 }

TCPIP0::127.0.0.2::inst0::INSTR
TCPIP0::127.0.0.3::inst0::INSTR

That is exactly the shape of the physical bench: every instrument is a box with its own IP, its own portmapper on UDP 111 and its device inst0. Going from the real bench to the simulated one, only the addresses change, neither the port nor the device.

On Linux every 127.x.x.x address is local and needs no setting up. On Windows only 127.0.0.1 answers. There, put the instruments on that IP, on the same port, and tell them apart by their device:

transporte: { tipo: vxi11, host: 127.0.0.1, puerto: 5025, device: inst0 }
transporte: { tipo: vxi11, host: 127.0.0.1, puerto: 5025, device: inst1 }

That second shape is the one of a VXI chassis or a LAN/GPIB gateway: a single address for several instruments. It works just as well, but it does force you to touch your software’s resource strings.

UDP port 111 is required, and it is privileged. On Linux, once:

sudo setcap 'cap_net_bind_service=+ep' /path/to/crucible

On Windows, start as administrator. Otherwise the bench does not start and says exactly this: it would rather not start than advertise instruments nobody can then find.

Anvil

The Anvil sequencer speaks SCPI over a socket, so it connects to Crucible with nothing special. The guide Anvil measures against a Crucible instrument (in Spanish) walks through it end to end.