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Nowadays no laptop is coming with serial port (D9), they only come with USB ports on it. Anyone has any idea how we are going to use them for communicating to PLCs and other serial devices?

I heard there are USB to serial convertors available in the market. How useful they are to communicate to say TSX Quatuam CPUs, Gateways etc. Any particular part no.??

And also any one used Toshiba satellite pro laptops in our work? Any comments on them?

Sorry guys, too many questions.

Your help is much appreciated.

Thanks.

In fact, there is one Croatian manufacturer still making laptops with serial port:
http://www.koncar-inem.hr/racunala/racunala/nada45.htm

Sometimes when you need a hardware handshake, you have problems with USB/Serial converter. We use Socket Ruggedized Dual Serial I/O PCMCIA Cards in several laptops (Dell, Toshiba...) and can use our PLC software with no problems.

KW

Belkin makes a very compact one that I've used with a number of devices. I've used a couple of others as well. The biggest thing that I've found is that if the manufacturer offers the option of using either their drivers or microsoft drivers - use the microsoft. Some of the software out there defaults to the microsoft names in the registry and will not find any other names - so you won't be able to find your comm port.

Davis Gentry

One among many technical reasons to dump Microsoft. There are choices written by techies for techies that are superior in every way for automation. And support for the user side is now very competitive. All we have to do is make the right choices and stand up a little. We are buying a multi million dollar press that is automated with Linux, RTLinux and a few other RTOS bits. Obviously, if the automation vendors won't change their stripes, they can become irrelevant. Clinging to MS after they become actually detrimental to automation (Vista?) isn't going to fool everyone forever.

Regards

cww

We ran into the same problem and have tried several different ones on several different serial devices, they work great as long as they handle 'ALL' the serial pins. Some that we have tried seem to act only as 3 pin serial connections (RX,TX,GND). Some of the PLCs require the other serial port pins to work as well.

You've got options as long as your software plays nice with Windows ports.

Sometimes a DOS app will work when you go full-screen (Alt-Enter) with your command prompt window when they won't otherwise. If not, you're screwed.

Another option for Windows Apps is a PCMCIA serial card. I've got a Quatech one & it works great.

That is, of course, assuming you have a slot. PCMCIA seems to be going away as well. A number of killer-diller laptops don't even have them anymore.

Michal Casterline
Frakes Engineering

Usb-serial converters are good, well those made by good name brands.
Although, with sonme plc´s i´ve had some bad experiences. The best way i´ve heard of i a PCMCIA card, some call them replicators, which give you one or more serial ports, in a non serial port laptop. What i´ve done since i work with plcs is simply to by a laptop that comes with serial port, but if that is not good for you, i would recommend you to buy a PCMCIA card, 200 dollars last time i heard in argentina (maybe in US in cheaper)

Good Luck

I Use a Serial converter to communicate to Bejers OP-Panels and whit my first converter it worked but not that good, the transfers were sometimes aborted and even sometimes it was not possible to get any communication between the panel and the pc. But then i lost my cabel it i got a new one now and it works great! never any problem whit the beijer panels. But I still cant communicate wiht Siemens S5 wiht my new converter...

All you need to do is buy a USB/RS232 converter. The trick is to buy one that powers the port of the device that you are trying to communicate with. Unfortuneately, this is easier said than done.

Go to http://www.keyspan.com and order the USA-19HS. I have never had a problem communicating with any PLC/RTU or any other device that I have needed to communicate with using a serial port.

Dear Sledrew,
Which type of PLCs have you tried?
The recommended USB- Serial Adapter is not externally powered but is bus powered?

Yes it is powered by the USB port.

Just found another usb/rs232/rs485/rs422 converter from this site: www.usb-serial-converter.com. Vista, Mac and Linux supported.

Steven

There are still laptops that have a serial port. If people would only buy laptops that meet their needs, we wouldn't have problems with the duopoly deciding what we should have. I would return such an inadequate machine and buy one with a serial port. I just looked at Dell and found several I don't care for their machines that much, but they do have serial ports.

Regards
cww

In reply to Curt Wuollet: There is almost nothing outside of technical applications (such as automation) that uses RS-232C serial ports anymore. The same applies to parallel printer ports. Getting rid of both on laptops saves cost and board space and has no significant effect on overall sales of computers. Floppy disk drives are options on most PCs now and few people miss them (the main use these days seems to be for copy protection master disks). PCMCIA adaptors for laptops are probably destined to go the same way.

Once the hardware manufacturers have dropped the hardware, Microsoft will drop support for these features from MS-Windows. Alternatively, they may not intentionally "drop" the features, but the features may not work properly anymore after some future "MS-Windows update" and Microsoft won't see any reason to spend man hours fixing a problem that only affects a handful of people.

The longer term solution is going to be to find USB or Ethernet to RS-232C serial converters that work in these applications. Perhaps someone could start a wiki where we could put information like this?

In the meantime, a lot of maintenance departments simply mount an ordinary desktop PC on a tool cart. All the special cables, manuals, adaptors, dongles, etc. go in the drawers, and if they need battery power they just add a UPS.

If you need something portable and still want to use commodity components, you could use a small form factor PC (e.g. Mini-ITX or similar), keyboard, mouse (or trackball), and an LCD monitor. If you attached them all together somehow, you would have a "portable" at the same price as a desktop PC and still have one or two PCI slots (for short cards at least). It would look a bit odd, but it would work.

Going forward, of course, the rational thing to do, considering that others are deciding for us that we no longer need the serial port, would be for PLC manufacturers to simply include a USB or Ethernet programming port. The right way to do it would be to have it isolated etc., so that we can use a widely available cable and no ridiculously expensive adapters or one-off plugs or any of the other pure and avaricious BS they try to palm off as necessary.

There is really no excuse for their "special" connectors or non- standard hardware when the cheapest (by virtue of volume) and best (by virtue of utility) solutions are OTS commodity items. It can't possibly cost more to integrate commodity silicon for these ports than any contrived non-standard and the connectors are proven and foolproof.

As for the current situation, there is still an adequate market to support serial ports and nothing on the current machines really adequately replaces them. I have yet to see a 1000' USB cable and Ethernet to serial conversion isn't too great except in certain circumstances. I think the denigration of serial ports is, at least in part, an assault on character-based devices in general to solidify an all GUI vision of the world. But there are still far too many things that RS232 and friends do best to simply write them out of the picture. I still believe that these folks that are scrambling for solutions simply bought a laptop that doesn't meet their needs. And whose fault is that? It should be a deal breaker when offered a machine which lacks basic necessary functionality for automation. Why do it, and deal with even more headaches when having to support five versions of Windows and DOS and many generations of shrinkwrap software? Isn't it about time this market becomes user driven rather than vendor driven? If people simply say no and follow up with their checkbook, I assure you this will change. There are many laptop vendors who would be very pleased to have all the automation and field service business simply by keeping their serial ports. There are machines for much smaller niches than that. Most of the crappy aspects of automation are with us simply because people accept them. The smallest amount of organization, agreement and cooperation could change any aspect of this market.

Regards
cww

Hi,

Omron's new CP1H PLC does have a USB port. This is the way forward.

Rgds,
Gabriel

In reply to Curt Wuollet: You've raise a number of detailed points about how things ought to be done which I will deal with in turn.

Curt Wuollet: "the rational thing to do... would be for PLC manufacturers to simply include a USB or Ethernet programming port."

MG: Ethernet would be much preferred over USB for PLC programming ports. Many PLCs already have this, and it allows flexibility in accessing the PLC remotely or over a network that just isn't practical with USB. USB might be suitable for connecting things like bar code readers (especially hand-held ones) or label printers.

Curt Wuollet: "have it isolated etc., so that we can use a widely available cable and no ridiculously expensive adapters or one-off plugs"

MG: I believe that Ethernet is already transformer isolated. And yes, anything other than standard plugs and cables would be foolish. To go directly from a PC to a PLC CPU without a switch you would need a cross-over cable, but those are still standard even if they are not as common as straight-through cables.

Curt Wuollet: "It can't possibly cost more to integrate commodity silicon for these ports than any contrived non-standard and the connectors are proven and foolproof."

MG: This is more or less what Siemens said in their product seminars when they introduced the Ethernet based Profinet to replace the RS-485 based Profibus. Note that Profinet is still a proprietary protocol (even more so than Profibus). The decision to use Ethernet was based on cost, not on any intention to be "open".

Curt Wuollet: "I think the denigration of serial ports is, at least in part, an assault on character-based devices in general to solidify an all GUI vision of the world."

MG: No, I think its just a lack of a consumer market. USB really is better than RS-232 for connecting flash drives, cameras, and music players. It is much faster, and can provide the power for things like flash drives. Another advantage is that most of these USB devices emulate a disk drive, so you can just plug them in without installing any special drivers. The old cameras which used RS-232 were a pain, because they all used different proprietary drivers.

Curt Wuollet: "There are many laptop vendors who would be very pleased to have all the automation and field service business simply by keeping their serial ports. There are machines for much smaller niches than that."

MG: They're usually pretty expensive too.

HP still sells a Laptop with a real serial port
Model: NX6320. At least in Australia anyway.

The most common Siemens S7-300 PLC's have had built-in Profinet/Ethernet ports for a couple years that can be used for programming or networking I/O.

It also wouldn't hurt to provide some basic functionality with public/Open protocols so integrators could communicate with the devices without being or paying a member of the Profibus club or other cartels. Being able to map a block of registers with TCP/IP packets would go a long ways towards being able to integrate systems with a few lines of glue code rather than an enormous monolith. ModbusTCP would be one way but if that's politically unfeasible, a simple x registers per packet with a checksum would suffice. Of course, once you can map registers, you have most of the magic of SCADA so I expect that to be expensive and complicated for a while yet. And this simple proto over ethernet would outperform most proprietary offerings, causing more paranoia among the bean counters. If people understand how close they are to having really useful and universal hooks for integration, they might get cranky with the hoops they have to jump through now. It would be truly trivial to provide this kind of thing, only the cash cows stand in the way. But that will pass, or PLCs as we know them will become irrelevant. All the broken or crippled forms of ethernet devised for cow protection will pass once they coexist with anything Open. Open protocols for automation simply make too much sense.

Regards

cww

I think that a large part of our problems with the "duoploly" stem from the fact that we as engineers are a tiny percentage of the PC buying public. How many people currently buying PCs or laptops require RS-232 communication? Or require that an OS be supported for two or more decades? MS has dimished the support for bit operations in their IDEs for the last two iterations - which almost noone outside of the engineering world cares about. When is the last time an IT type was worried about doing a bitwise OR on the data coming across a serial port???

siggghhhhhhhhh

Davis Gentry

I imagine that a PCMCIA serial port would be the cheapest and easiest way to go. USB serial adapters sometimes cause problems.

----
Nathan Boeger
http://www.inductiveautomation.com
Total SCADA Freedom

When I looked recently, HP was still selling laptops with one serial port.

DELL still has some models with serial ports.
I have a D820 with a real serial port that works with Quantum PLCs

You can still get laptops with serial if you ask for it, probably not of the shelve those.

Telemecanique sell an SR2CBL06 USB to serial convertor cable that works wirth Concept and Proworox. Must have Windows XP pro, or 2000. This cable is used inconjunction with the standard Quantum / momentum serial cable.

can't say about TSX, it may depend on the software package you're running. You may use USB/RS232 converters (or even Ethernet/RS232 converters if latency is not an issue) for simple communications, but if you are planning to use Siemens S5 package you'll need a true serial port providing proper interrupts. In that case, a PCMCIA card with RS232 port is the solution.

I recently evaluated the Dell Latitude (some colleagues of mine bought the D820 version) it comes with an on-board serial port. There's also a rugged (and expensive) version, the Dell Latitude ATG.

regards
Luca Gallina

Dell Latitude still comes with Serial port.

As for as experience with external serial port adaptors goes, USB to RS232 do work for some PLCs but not with all PLCs. PCMCIA serial port adaptor are the best bet for PLC applications.

My experience with USB serial port adapters is mixed. They seem to work OK most of the time but my PCMCIA serial port adapter works all the time EXCEPT that no USB or PCMCIA serial port adapter will work with the AB PIC driver. It will only work with a built in serial port. I guess they want to sell more USB to DH485 adapters instead of PIC modules.

There seems to a functional difference between USB serial adapters that have a UART and those that those that do not. The same applies to PCMCIA and Xtend cards which often act like USB adapters for this purpose.

Sorry, I do not know why this is true, but I know from experimenting with them that it is. I'm doing OK so far with an adapter from SIIG. You could also look at National Instruments and Sealevel.

You will need a USB to Serial Convertor. There are too many standrad convertor cables available in market. However this will work only if the PLC programming software which you are using is Windows based and not DOS based.

I just bought a Dell Latitude 520 that has a serial port. I also have tried USB-232 adapters, and the only ones that I have not had any issues with are the Edgeports, which are carried by B&B Electronics.

Hi,

We've had the same problem, but there is a solution... Dell Latitude 620/630 and the 820/830 series still have the "forgotten" serial port. Just go to dell.com and check it out yourself. We just bought 2 630s and the serial port works with old DOS applications. Even the old Siemens S5 PLC software works with it!!

Tlynyrd
(ytsejam prog-rocks-solid)

Try the serial converter from this site: http://www.serial-converter.com

Steven

I have a Dell Latitude with serial port, I purchased it from the Rockwell vendor to run RSLogix5000. I had the vendor load the software but found it extremely slow. I sent it back and they zapped the OS and reloaded regular XP professional. It's much faster. Apparently the Dell version has so much C*** included.

Hope this helps someone.

Roy