Grant Edwards wrote:> On 2011-01-14, Oliver Betz <OBetz@despammed.com> wrote:[ ... ]>> But I suggest this only as a solution separate from my device (not >> integrated), because the installation requires Administrator rights, >> IOW is much more intrusive than I want one of my designs to be. > > Windows doesn't support the common USB-serial chips (FTDI, PL2303, > etc.) right out of the box?!?!? Good grief, those chips have been > around for ages.I was surprised too. The FTDI devices I use are class-compliant and stock Ubuntu connects them as /dev/ttyUSB0 , ..1 , ..2 , etc. (some others as /dev/ttyACM* .) The pain at the user end is to figure out which one is which. Thank you, PCI bus... Mel.
Do you still use "RS232" or something else?
Started by ●January 14, 2011
Reply by ●January 15, 20112011-01-15
Reply by ●January 15, 20112011-01-15
On 2011-01-15, Mel <mwilson@the-wire.com> wrote:> Grant Edwards wrote: > >> On 2011-01-14, Oliver Betz <OBetz@despammed.com> wrote: > [ ... ] >>> But I suggest this only as a solution separate from my device (not >>> integrated), because the installation requires Administrator rights, >>> IOW is much more intrusive than I want one of my designs to be. >> >> Windows doesn't support the common USB-serial chips (FTDI, PL2303, >> etc.) right out of the box?!?!? Good grief, those chips have been >> around for ages. > > I was surprised too. The FTDI devices I use are class-compliant and stock > Ubuntu connects them as /dev/ttyUSB0 , ..1 , ..2 , etc. (some others as > /dev/ttyACM* .) The pain at the user end is to figure out which one is > which. Thank you, PCI bus...If you take the time to put in a device-name and serial number, it's not too bad, but many people don't, and then there's no way to tell apart two completely different devices that happen to use the same chip. I assume it requires an additional I2C EEPROM or something like that, so I guess it would cost another $0.30 or so. -- Grant
Reply by ●January 15, 20112011-01-15
On Jan 14, 12:36=A0pm, Tilmann Reh <usenet2007nos...@autometer.de> wrote:> Hello Oliver, > > > although most of our (industrial) clients still use to have computers > > with a "real" serial port, I observe a small but increasing number > > struggling with bad USB adapters and asking for other interfaces. > > > Therefore I'm reconsidering the best suited interface for device > > configuration and diagnosis. > > > Do you still use EIA-232? > > Yes, definitely. > > > Customers complaining? > > Sometimes - but when it comes to talking about cost, they all agree to > RS-232 again. :-) > > > What do you consider a suitable "successor"? > > There is none. RS-232 is by far the cheapest standard communication you > can get, and it works perfectly fine even with the smallest > microcontrollers. > > Sometimes, USB is an alternative.I'm not sure that the recurring cost of 232 is significantly lower than a small MCU implementing a USB stack. I have yet to add USB to a product, but I would say 232 is on it's last legs. Development cost is a different matter. 232 is so simple, a college freshman can implement it... and I did as a freshman... Rick
Reply by ●January 15, 20112011-01-15
Clifford Heath wrote:> On 01/14/11 23:13, Oliver Betz wrote: >> Do you still use EIA-232? Customers complaining? > > Don't know, but I can tell you what I wished for, even 25 years > ago when I had almost daily fights with RS-232 cabling. > > A symmetrical standard based on a hermaphrodite 8-wire connector. > > My-ground, I'm-ready, my-data, my-power/my-inverted-data (if > differential), and the corresponding 4 inputs.If you go for inverted data as well that is 5 connections each way. I'd consider two differentially driven circuits in each direction as adequate. One TX pair and a Ready or Sync pair.> Put them all in a symmetric 8 conductor socket that's half > male, half female, so if you can plug it in, and have the > right data-rate, it'll work. In differential mode, it would > be good for half-mile runs at decent data rates on CAT-5.If you are thinking like the LEMO half and half connectors, they are somewhat pricey.> Center the data levels at 2.5V, with swings to 0 and 5V so you > don't need elevated supplies from a 5V system, and you can > easily transfer useful power, perhaps 100mA, for low-power > peripherals, even when using differential transmission. > > I don't get why hermaphrodite connectors never took off, it > just seems like a no-brainer. They might be a little harder > to make, but in volume would surely be cheaper than DE-25s.Maybe the price. -- ******************************************************************** Paul E. Bennett...............<email://Paul_E.Bennett@topmail.co.uk> Forth based HIDECS Consultancy Mob: +44 (0)7811-639972 Tel: +44 (0)1235-510979 Going Forth Safely ..... EBA. www.electric-boat-association.org.uk.. ********************************************************************
Reply by ●January 15, 20112011-01-15
On Jan 15, 2:41=A0am, Glenn <glenn2...@gmail.com> wrote:> On 15 Jan., 02:01, Clifford Heath <n...@spam.please.net> wrote: > > > > > On 01/14/11 23:13, Oliver Betz wrote: > > > > Do you still use EIA-232? Customers complaining? > > > Don't know, but I can tell you what I wished for, even 25 years > > ago when I had almost daily fights with RS-232 cabling. > > > A symmetrical standard based on a hermaphrodite 8-wire connector. > > > My-ground, I'm-ready, my-data, my-power/my-inverted-data (if > > differential), and the corresponding 4 inputs. > > > Put them all in a symmetric 8 conductor socket that's half > > male, half female, so if you can plug it in, and have the > > right data-rate, it'll work. In differential mode, it would > > be good for half-mile runs at decent data rates on CAT-5. > > > Center the data levels at 2.5V, with swings to 0 and 5V so you > > don't need elevated supplies from a 5V system, and you can > > easily transfer useful power, perhaps 100mA, for low-power > > peripherals, even when using differential transmission. > > > I don't get why hermaphrodite connectors never took off, it > > just seems like a no-brainer. They might be a little harder > > to make, but in volume would surely be cheaper than DE-25s. > > > Clifford Heath. > > Hi Clifford > > Please look here - the nearest EIA-232 wiring supporting some of your > wishes - via 8P8C aka "RJ-45": > > http://www.lammertbies.nl/comm/cable/yost-serial-rj45.html > > - > > The USB standard ought to be with for a long time - why?: > > It has only 1 twisted pair for bidirectional communication. It can not > get any simpler in hardware ! > > and 0V and to some extent optionally +5V.One time, many years ago, I developed a standard pinout for an RJ-45 connector that allows every device to talk to every device. It had two grounds and the other pins were paired, TX-RX, RTS-CTS, DTR-DSR and the RJ-45 cable was wired as a crossover always. That part worked pretty well. But you still needed up to four adapters just for one size connector, the DB-25 still being the dominant size. By the time the DB-9 was adopted as an EIA standard, the DB-25 was getting to be rare and I found a lot less trouble getting things to pair up ok without the RJ-45. Now it seems like the male DB-9 connectors are all wired DTE while the female DB-9 connectors are all wired DCE so one cable with a null modem on one end if needed does the trick. If push comes to shove, and you find a DB-25 connector a DB-9 to DB-25 usually does the trick with the other stuff. But I'm looking forward to the day when 232 is replaced by USB, not because laptop makers refuse to have them in the machine, but because USB is so easy to add there is no reason to use 232. Rick
Reply by ●January 15, 20112011-01-15
On Sat, 15 Jan 2011 09:49:28 -0800 (PST), the renowned rickman <gnuarm@gmail.com> wrote:>On Jan 15, 2:41�am, Glenn <glenn2...@gmail.com> wrote: >> On 15 Jan., 02:01, Clifford Heath <n...@spam.please.net> wrote: >> >> >> >> > On 01/14/11 23:13, Oliver Betz wrote: >> >> > > Do you still use EIA-232? Customers complaining? >> >> > Don't know, but I can tell you what I wished for, even 25 years >> > ago when I had almost daily fights with RS-232 cabling. >> >> > A symmetrical standard based on a hermaphrodite 8-wire connector. >> >> > My-ground, I'm-ready, my-data, my-power/my-inverted-data (if >> > differential), and the corresponding 4 inputs. >> >> > Put them all in a symmetric 8 conductor socket that's half >> > male, half female, so if you can plug it in, and have the >> > right data-rate, it'll work. In differential mode, it would >> > be good for half-mile runs at decent data rates on CAT-5. >> >> > Center the data levels at 2.5V, with swings to 0 and 5V so you >> > don't need elevated supplies from a 5V system, and you can >> > easily transfer useful power, perhaps 100mA, for low-power >> > peripherals, even when using differential transmission. >> >> > I don't get why hermaphrodite connectors never took off, it >> > just seems like a no-brainer. They might be a little harder >> > to make, but in volume would surely be cheaper than DE-25s. >> >> > Clifford Heath. >> >> Hi Clifford >> >> Please look here - the nearest EIA-232 wiring supporting some of your >> wishes - via 8P8C aka "RJ-45": >> >> http://www.lammertbies.nl/comm/cable/yost-serial-rj45.html >> >> - >> >> The USB standard ought to be with for a long time - why?: >> >> It has only 1 twisted pair for bidirectional communication. It can not >> get any simpler in hardware ! >> >> and 0V and to some extent optionally +5V. > >One time, many years ago, I developed a standard pinout for an RJ-45 >connector that allows every device to talk to every device. It had >two grounds and the other pins were paired, TX-RX, RTS-CTS, DTR-DSR >and the RJ-45 cable was wired as a crossover always. That part worked >pretty well. But you still needed up to four adapters just for one >size connector, the DB-25 still being the dominant size. By the time >the DB-9 was adopted as an EIA standard, the DB-25 was getting to be >rare and I found a lot less trouble getting things to pair up ok >without the RJ-45. Now it seems like the male DB-9 connectors are all >wired DTE while the female DB-9 connectors are all wired DCE so one >cable with a null modem on one end if needed does the trick. If push >comes to shove, and you find a DB-25 connector a DB-9 to DB-25 usually >does the trick with the other stuff. > >But I'm looking forward to the day when 232 is replaced by USB, not >because laptop makers refuse to have them in the machine, but because >USB is so easy to add there is no reason to use 232.RS-232 can (at low baud rates) tolerate a couple of orders of magnitude longer cables than USB. Of course we have Ethernet for that, but it adds a lot of complexity, both to the device and often for the user to set it up.>RickBest regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by ●January 15, 20112011-01-15
Grant Edwards wrote: [...]>> Since several people voted for USB - UART adapters, usually FTDI FT232 >> flavour: That's also my preferred solution for people not being >> long-sighted enough to by a suitable computer with a real comm port. >> >> But I suggest this only as a solution separate from my device (not >> integrated), because the installation requires Administrator rights, >> IOW is much more intrusive than I want one of my designs to be. > >Windows doesn't support the common USB-serial chips (FTDI, PL2303, >etc.) right out of the box?!?!? Good grief, those chips have been >around for ages.Even if you use a CDC USB device with the Windows drivers, you have to build a custom INF file, and you need admin rights to install them. So the question is not only whether Windows has drivers (it has for CDC), but whether I need to "install" any drivers. I didn't try it yet, but as far as I see, a HID doesn't need explicit installation, especially no admin rights under Windows. But of course, you need custom software to make the data accessible, at least the equivalent to a terminal program. Oliver -- Oliver Betz, Muenchen (oliverbetz.de)
Reply by ●January 15, 20112011-01-15
rickman wrote: [...]>But I'm looking forward to the day when 232 is replaced by USB, not >because laptop makers refuse to have them in the machine, but because >USB is so easy to add there is no reason to use 232.Maybe I have a different understanding of "easy". Using a terminal program (e.g the one supplied with the PC operating system) is easy. I can guide a customer's technician on the phone to do it. He doesn't even need Internet access there. Providing software to access the USB HID data for every operating system is IMNSHO less easy. Windows X86, Windows 64 bit, Linux, Mac OS X, to be supported for more than ten years. I don't like to do it. Oliver -- Oliver Betz, Muenchen (oliverbetz.de)
Reply by ●January 15, 20112011-01-15
rickman wrote: [...]>I'm not sure that the recurring cost of 232 is significantly lower >than a small MCU implementing a USB stack. I have yet to add USB to aFor the MCU side, USB can be cheaper then EIA-232. Oliver -- Oliver Betz, Muenchen (oliverbetz.de)
Reply by ●January 15, 20112011-01-15
On 1/15/2011 3:08 AM, Oliver Betz wrote:> D Yuniskis wrote: > >>>> I am going Ethernet - tcp/ip, VNC (RFB) access to my stuff - this >>>> leaves >>>> the communication to whatever is at the other side to the pixel/mouse/ >>>> keyboard >>>> level. >>>> Latest thing to be proudly shown: http://tgi-sci.com/tgi/nmca3.htm >>>> (board can be seen at http://tgi-sci.com/misc/nmc3top.gif ) >>> >>> this uses Ethernet for the _main_ operation. That's different from >>> what I wrote ("device configuration and diagnosis"). >> >> You would have to clarify what you *really* intend by that >> statement. >> >> E.g., if your device is "malfunctioning" (read that as "not functioning >> as could be reasonably expected by a typical user") then you can be >> implying that something is "FUBAR" and your network subsystem *isn't* >> functioning. Sort of like telnet'ing to a host because your GUI >> login isn't configured properly (i.e., "effectively unavailable"). > > _My_ devices usually have no main "network" connection suitable for > "free form" diagnosis. They are offered without any "Network" (just > 24V digital I/O) or with CAN (-open) or the He-Who-Must-Not-Be-Named > industrial bus from Big S. > > "Free form" diagnosis means for example that the user can start some > self tests and gets results in human readable form. That's easy with a > terminal program. > > With CANopen or Profibus, I had to get access to this bus from the PC > and to supply host software to achive a similar result. That's > impossible in most cases. > > Therefore I need a simple "interactive" access to the device. > Currently EIA-232 if possible. Or UART data over 24V I/O with a > primitive (even passive) level converter for small sensors. We did > this long before IO-Link became popular.But you also need that to be some interface that the (typical) user will have ready access to. What distances are you concerned with? And, how "interactive" does it have to be? E.g., entering the current date is more interactive than *picking* the day-of-week.>> OTOH, if your device is robust enough to be operational *including* >> the networking aspects, then you could still support "configuration >> and diagnosis" over the wire. > > If I had Ethernet anyway as Didi's spectrometer has, I would of course > offer configuration and diags there. > > But I'm afraid our users won't use plain/clean Ethernet but switch to > "Screwed-Up-Profibus" which I won't implement unless I'm forced to.If you can live with the (short) distance limitations of USB, what if you made your device look like a mass storage device. I.e., damn near every USB host out there will recognize a USB "disk drive". User can mount the drive (which is often automatic) and then access X:\index.html to interact with it. That *static* page (i.e., a "file" on your device) can have links to: X:\status.html, X:\log.html, X:\diagnostics.html, etc. You don't even need a "web server" in your device -- instead, you watch to see which "files" are accessed and in which order. (I don't know what information you have to get from the user nor what you have to provide *to* him so I'm just suggesting a framework that you would have to evaluate)
