Program access to DMM 7510. A lot of different protocols. - Page 1
Forum section: electronics / general

author: MegaVolt
author_rank: Frequent Contributor
timestamp: November 09, 2018, 08:57:37 am
content: I'm trying to understand how to programmatically control the device. And I find a lot of different interfaces and protocols.Maybe there is somewhere to read a brief explanation about them? How to exchange data? What speed is obtained etc.The hardware of connection is clear.Device -> cable -> board (GPIB / USB / LAN) -> drivers for the board (GPIB / USB / LAN)But then I start to get confused.LAN:- TCPIP: Instrument is communicating through a LAN interfaceDirect communication with the device. Protocol TSP / SCPI? Where can I read the details of the exchange?- Telnet: Instrument is communicating through TelnetDirect communication with the device. Protocol TSP / SCPI?- VXI-11: Instrument is communicating using VXI-11Need to install additional VISA driver? Where to read the exchange protocol?USB:USBTMC: Instrument is communicating through a USB interfaceNeed to install an additional driver? Is he also a VISA?But there are still LabView drivers. Are they on their own? What do they give? Is there a description of the exchange protocol?And there is also an IVI driver.I'm completely confusedPlease correct me.Which protocol is the fastest. What protocol does not depend on the type of hardware connection? Which is easier to implement?Where to read something about it?

author: s8548a
author_rank: Regular Contributor
timestamp: November 10, 2018, 09:25:14 am
content: I don't have a bench DMM, but recently played a bit with Oscilloscope and PSU over SCPI.Quote from: MegaVolt on November 09, 2018, 08:57:37 amI don't have the experience to tell which protocol is fastest, but it's good to read about LXI LAN Latency:http://www.lxistandard.org/About/QAndA.aspx#6I believe SCPI is hardware connection independent and easy to implement.Please have a look at these Opensource solutions EEZ Studio & LXI Tools:https://www.eevblog.com/forum/testgear/eez-studio-for-accessing-your-(scpi)-instruments/msg1651034/#msg1651034https://lxi-tools.github.io/

author: alm
author_rank: Super Contributor
timestamp: November 10, 2018, 09:54:38 am
content: The actual commands will be all SCPI, no difference there. Only the way things like bus triggers, polling and interrupts (SRQ) are handled will be different. I expect GPIB, VXI-11 and USB-TMC to be the most full-featured in that regard. The LXI standard references raw TCP connections, Telnet and VXI-11 as transport protocols, so try starting with the LXI standard if you want to implement them. Common VISA implementations should support all of them. You don't need any drivers for raw TCP or telnet, however.Which is the fastest? Latency? Sustained throughput? Peak throughput? For guaranteed latency probably GPIB, then VXI-11? For throughput, probably either USB-TMC or raw TCP, though I expect the various LAN options to be very close.Easy to implement. For a bare micro, GPIB (that was originally implemented using discrete logic gates). For a common PC, raw TCP or Telnet, as long as you don't need any of the features they don't support.LabView and IVI give you a high level abstraction on top of the SCPI, which are on top of whatever transport VISA supports. So you can do things like "I don't care what DMM you are, but measure 5V for me with 1 mV resolution", instead of ":SENSE:VOLT:DC:RANGE 5" etc.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: November 10, 2018, 10:30:07 pm
content: Quote from: s8548a on November 10, 2018, 09:25:14 amThank you so much!!! The picture on the last page is what I was looking for !!!QuoteUnfortunately, they are only under Unix.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: November 10, 2018, 10:41:39 pm
content: Quote from: alm on November 10, 2018, 09:54:38 amGPIB requires an additional fee in the computer. USB and LAN already haveQuoteThanks for clarifying. So it became clear