Products > Test Equipment

Affordable Power Supply with Ethernet/LXI?

<< < (3/5) > >>

tautech:

--- Quote from: 44kgk1lkf6u on March 14, 2024, 04:22:45 am ---I had access to both a Siglent SPD3303X ....
While we're on it, their banana plugs also have a spacing that is not ¾ in.


--- End quote ---
Correct, instead 20mm however that does not apply to the SPD1000X series which do have 3/4" terminal spacings.

Berni:
The Rigol DP832 is also a good programmable lab PSU, costs a bit more but has 3 independent channels.

Tho aiming for all 100% Ethernet for your SCPI automation needs is probably not the best idea, since many instruments don't have ethernet (it is more common on modern gear, but still not ubiquitous) and brindging LAN onto instruments with RS232 or USB is not that simple, probably easiest is with a RaspberryPi.

USB is a lot easier to convert just about anything into, so you can have all of your bench going into a big USB hub and then you can have a simple single cable going to your PC.

I do have a Agilent GPIB to LAN bridge in my equipment rack to help connect the heavy ancient boatanchors from the 80s and 90s. Since all of them are so old they only speak GPIB. But since you can daisy chain GPIB, it made the GPIB to LAN bridge a convenient solution. 

alm:

--- Quote from: tautech on March 14, 2024, 12:36:40 am ---So why would there be a list of App notes on remote control usage ?
https://siglentna.com/application-notes/spd1000x-series/

--- End quote ---
Because their sales people want to sell the power supplies for remote control, but the engineers are not willing to guarantee any specifications regarding remote control? Would you use an op-amp without an offset voltage specification for an application where offset voltage is important? Any feature that does not have guaranteed or typical specifications is clearly not a priority for the manufacturer. More like a "sure, we can add a LAN port for $5" that came late in the product design cycle.

nightfire:
Wow, thanks again for the input and the insights in the inner working of a Power Supply regarding update cycles etc.!

To get a better grasp of the situation: The stuff is for my little home lab, where I also will use it to explore things- so usage for partly educational purpose ;-)
And, as my existing equipment is not bad, it is whether not connectable at all (some small <100€ Power supplies, some of the linear and old), Multimeters (my bench DMMs are more than 20 years old), and some new stuff that has Ethernet.
Those Ethernet-capable devices are a Korad electronic load and some entry level Rigol scope. So for me the though was, that I could look while expanding my gear for remote control for recurring tasks I would perform, where repeatability makes sense or is crucial to the task.

As for connectivity, Ethernet for me is easier to maintain than a load of USB devices, and in my experience less prone to error that USB->Serial connections, at least at the level of swtiching/cabling involved. Not speaking tho for the inner goods or implementation in the device(s) themselves.
In my last job I was also responsible for administering the OOBMS platform in a datacenter, mainly consisting of cyclades TS3000 console servers, and some power monitoring devices where we used Modbus over RS485 and over serial converters to Ethernet (to the main Server)- so I eperienced some share of stuff that can happen in this field.

Anyway ,for the upcoming projects even a mediocre response time or readout behaviour of the mentioned Siglent PS are ok enough for the task- when I do some comparison and tests of charging/discharging camera batteries and similar stuff, I am talking about changing parameters and getting them every 1s or 5s, so no need for immediate response. Also some measurements via other multimeters would be taken somewhere, that would be deemed authoritative for the task at hand, so I do not need to rely on precision measurements from the PS itself.

Interesting idea to get some USB->GPIB converter, or Ethernet ->GPIB.
I admit the the open source Xyphro GPIB to USB looks nice, so I would really like to get some hands-on experience- Penguin compatibility is nice, because there is another factor that I took into account whilst planning purchases: I will as one of the upcoming projects rig up an old PC I assembled for cheap from really solid parts as a Unix-based Workstation under FreeBSD and also do some measurement work here.
So Ethernet/LXI could be the protol that will involve the least number of drivers and proprietary windows programs to get some communication done.

Ethernet->LXI converters are a cool idea, I would like to hear how well they perform under non-Windows environments.

Berni:
The reason you had constant issues with Modbus and RS485 is that they are shitty protocols that are often implemented in a way that is not robust enough for the environment they end up used in.

You should not need any special drivers to do things over USB. All properly made test equipment should be using the same USBTMC driver. Any PC side VISA implementation you use will automatically detect and identify the instrument as soon as you plug it in. If it does not simply work out of the box like that then the manufacturer of your test gear has fucked up.

That being said RS232 is indeed not plug and play like that. You do need to specifically tell the VISA software to treat a certain COM port as a instrument, but once you do that you are set forever. When you unplug and replug it it will always pick it up (Unless you are using shitty chinese USB to RS232 dongles that don't have serial numbers, throw those in the trash please). Some cheep instruments that have USB actually have a USB to RS232 chip inside, so those are configured the same way.

Also there is nothing wrong with having a mix of Ethernet, USB, GPIB, PXI..etc test gear connected to a computer. They all show up in the VISA software exactly the same once detected, communication to all of them is done trough the exact same call to the VISA dll function. So your test automation script does not even know over what physical protocol it is talking to the instrument, it is the job of the VISA library to take care of that nitty gritty.

Also don't just blindly go for the 'standard' National Instruments VISA software, it is one of the worst bare bones implementations. I personally recommend using Keysight IO VISA as it has lots of nice features and it is also free. (Rigol also has its own VISA called UltraSigma or something, i am not that much of a fan of it) And don't worry it is not Keysight instruments only. It will talk to any IVI or PXI compliant instrument, or even talk to your own DIY made test equipment as long as you follow the standards.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod