Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • World
  • Users
  • Groups
Skins
  • Light
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (No Skin)
  • No Skin
Collapse
Code Project
  1. Home
  2. The Lounge
  3. 20mA current loop

20mA current loop

Scheduled Pinned Locked Moved The Lounge
helpquestion
15 Posts 10 Posters 0 Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • L Lost User

    CodeWraith wrote:

    I think that current loops are now a thing that you can find in a museum, or am I wrong there?

    Lots of hardware in the maritime industry still using current loops today. Kongsberg, Baker Hughes, Hatteland, Rolls-Royce... many others, too many to name.

    C Offline
    C Offline
    CodeWraith
    wrote on last edited by
    #6

    Ah, ok. Reliability instead of shiny and new. Makes sense.

    I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

    L 1 Reply Last reply
    0
    • C CodeWraith

      I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included. When was the last time you saw any device use that or at least have that option? The problem is more relevant today than ever before, but I think that current loops are now a thing that you can find in a museum, or am I wrong there?

      I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

      honey the codewitchH Offline
      honey the codewitchH Offline
      honey the codewitch
      wrote on last edited by
      #7

      CodeWraith wrote:

      I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included.

      I actually run into things that use serial in the IoT realm and while i'm usually using a USB to serial bridge like a CP2102 or a CH340, some little devices break out to RS232. The thing is, I have no idea what a 20mA current loop is or why it could replace the functionality of a serial interface? And it's something I feel like maybe I should understand. What sorcery is this?

      To err is human. Fortune favors the monsters.

      C 1 Reply Last reply
      0
      • C CodeWraith

        I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included. When was the last time you saw any device use that or at least have that option? The problem is more relevant today than ever before, but I think that current loops are now a thing that you can find in a museum, or am I wrong there?

        I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

        CPalliniC Offline
        CPalliniC Offline
        CPallini
        wrote on last edited by
        #8

        Cobol is still used, my dear.

        "In testa che avete, Signor di Ceprano?" -- Rigoletto

        In testa che avete, signor di Ceprano?

        1 Reply Last reply
        0
        • C CodeWraith

          Ah, ok. Reliability instead of shiny and new. Makes sense.

          I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

          L Offline
          L Offline
          Lost User
          wrote on last edited by
          #9

          CodeWraith wrote:

          Reliability

          Yep, I just looked through the Raytheon and L3 products and see they are still using them too. I use to work with alot of maritime hardware. We were converting currrent loop to RS232 to interface with our PLC back then.

          1 Reply Last reply
          0
          • C CodeWraith

            I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included. When was the last time you saw any device use that or at least have that option? The problem is more relevant today than ever before, but I think that current loops are now a thing that you can find in a museum, or am I wrong there?

            I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

            L Offline
            L Offline
            lmoelleb
            wrote on last edited by
            #10

            Last I heard of it was the Lenz RS-Bus used in model trains - no idea if it is still used, I just read about it back 5-10 years ago. I have been tempted to hook up a remote sensor with current source to run two wires only (as an alternative to 1-wire but less prone to noise or capacitive problems on longer runs). Never got off the ground though, and I do not remember what it was I wanted to sense, so it was probably not important. :)

            1 Reply Last reply
            0
            • honey the codewitchH honey the codewitch

              CodeWraith wrote:

              I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included.

              I actually run into things that use serial in the IoT realm and while i'm usually using a USB to serial bridge like a CP2102 or a CH340, some little devices break out to RS232. The thing is, I have no idea what a 20mA current loop is or why it could replace the functionality of a serial interface? And it's something I feel like maybe I should understand. What sorcery is this?

              To err is human. Fortune favors the monsters.

              C Offline
              C Offline
              CodeWraith
              wrote on last edited by
              #11

              Old and ancient magic, used for teletypes and later for computer terminals. As an old standard, it was slower than RS232, but is also known for its high noise immunity.

              I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

              L 1 Reply Last reply
              0
              • C CodeWraith

                Old and ancient magic, used for teletypes and later for computer terminals. As an old standard, it was slower than RS232, but is also known for its high noise immunity.

                I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

                L Offline
                L Offline
                Lost User
                wrote on last edited by
                #12

                CodeWraith wrote:

                also known for its high noise immunity

                Cable length[^] is a limiting factor for RS232. Also the reason why some industries are still using current loops. :)

                Mircea NeacsuM 1 Reply Last reply
                0
                • L Lost User

                  CodeWraith wrote:

                  also known for its high noise immunity

                  Cable length[^] is a limiting factor for RS232. Also the reason why some industries are still using current loops. :)

                  Mircea NeacsuM Offline
                  Mircea NeacsuM Offline
                  Mircea Neacsu
                  wrote on last edited by
                  #13

                  … or RS485 I’d say current loop is confined these days mostly to analog 4-20 mA sensors

                  Mircea

                  L 1 Reply Last reply
                  0
                  • Mircea NeacsuM Mircea Neacsu

                    … or RS485 I’d say current loop is confined these days mostly to analog 4-20 mA sensors

                    Mircea

                    L Offline
                    L Offline
                    Lost User
                    wrote on last edited by
                    #14

                    Mircea Neacsu wrote:

                    current loop is confined these days mostly to analog 4-20 mA sensors

                    Yes, I would say it's the industry standard in some areas. There are many thousands of industrial sensors using current loops even today.

                    1 Reply Last reply
                    0
                    • C CodeWraith

                      I just stumbled over an old construction article where an option to use a 20mA current loop instead of RS232 is included. When was the last time you saw any device use that or at least have that option? The problem is more relevant today than ever before, but I think that current loops are now a thing that you can find in a museum, or am I wrong there?

                      I have lived with several Zen masters - all of them were cats. His last invention was an evil Lasagna. It didn't kill anyone, and it actually tasted pretty good.

                      theoldfoolT Offline
                      theoldfoolT Offline
                      theoldfool
                      wrote on last edited by
                      #15

                      Hardly qualifies as a loop but I have a current sensing switch that turns on a device when a pump starts up. Monitors the current on the AC line to the pump.

                      >64 Some days the dragon wins. Suck it up.

                      1 Reply Last reply
                      0
                      Reply
                      • Reply as topic
                      Log in to reply
                      • Oldest to Newest
                      • Newest to Oldest
                      • Most Votes


                      • Login

                      • Don't have an account? Register

                      • Login or register to search.
                      • First post
                        Last post
                      0
                      • Categories
                      • Recent
                      • Tags
                      • Popular
                      • World
                      • Users
                      • Groups