Where Is Eric Nelson When You Need Him?

[Derek Frerichs]

I have a cable problem! Actually it is a laptop problem.
We got a new Toshiba laptop and when we went to the plant the other day to hook up to the Modicon Compact 984 we discovered that the new laptop has no serial port. Is there a way to build one compatible with the USB? If so does anyone have a pin out?

I've seen some cables advertised that look like they might do the trick but it might be a little more fun to build one and save the $50.

[Eric Nelson]

I'm here, but can't help you with this one....

There are plenty of guys in this forum with answers about which USB to serial adapters work/don't work with which PLCs. Personally, I'd use a PCMCIA (PC Card) to serial adapter, though these have their own issues.

Blame the guy who spec'd the new laptop.... Why did they get one without legacy ports????? :smas:

Good luck!!!

-Eric

[Derek Frerichs]

Who knows what powers the brains of the guys in the carpeted offices. We gave the specs and they said No Problem. Then when we got it we asked where was this, where was that? The usual questions... They reply was that this was a good deal and you did not need all that stuff anyway. Then the serial port! Something we were very specific about! The reply to that was "This is a problem?" Don't get me wrong, I love my AC in the office but these guys really should try to leave their offices from time to time and get a look at the real world.

Oh my I guess that was a sore subject, sorry. Anyway, thanks for the help big guy. I did find a great source on the USB from one of the old posts last night and I am going to try and see if I can prove to somebody in the carpeted offices that I really need it and the exact one that I specify. May the gods of purchasing smile on my req.

Thanks again!
Derek

[Steve Bailey]

Derek,

FWIW, one of my customers was in a similar situation a few years ago. Their IT department had put some strict specs on what computers could and could not be purchased, what OS they they had to have, what software had be bundled with them, who had administrator privileges, etc.

The maintenance department needed a new laptop for programming their PLCs, but they knew that the IT Dept. specs would render the laptop incompatible with some of the PLC software they needed to run.

The solution was to have me, their PLC vendor, purchase a laptop and resell it to them as a 'PLC Programmer". It helped that the Purchasing Manager was feuding with the IT Manager at the time.

[ganutenator]

You obviously missed my previous post. Here is a cut and paste. Definetly works for Modicon, haven't tested with a SLC yet.


My former Problem: I originally found problems with newer computers and going online with the Modicon Micro via the Serial port. I am running Windows 2k and when I would work online, the connection was very slow. Plus, certain tasks like search and online editing didn't even work.

My Solution: I found this USB serial adapter from Keyspan (www.keyspan.com) part number USA-19QW that has fixed the problem. When I go online with the Modicon Micro now, it is super fast. All my former problems have disappeared. Plus, now I have a free serial port to connect to the HMI.

I don't know how much it costs since I found it in the desk drawer of a former employee that was using it with XP, but I think it is about $60.00.

P.S. If anyone knows what the actual cause of the problem is, or if there is a plain windows work around, that would be cool to know too.

[rsdoran]

I didnt miss your previous post, and made some suggestions. Try it with the SLC (especially a PIC) if works you are ok. If not go back and look at other options/suggestions I posted.

[akreel]

Originally posted by Steve Bailey
Derek,

FWIW, one of my customers was in a similar situation a few years ago. Their IT department had put some strict specs on what computers could and could not be purchased, what OS they they had to have, what software had be bundled with them, who had administrator privileges, etc.

The maintenance department needed a new laptop for programming their PLCs, but they knew that the IT Dept. specs would render the laptop incompatible with some of the PLC software they needed to run.

The solution was to have me, their PLC vendor, purchase a laptop and resell it to them as a 'PLC Programmer". It helped that the Purchasing Manager was feuding with the IT Manager at the time.

Yeehah! I need a new "portable email access tool."

[Derek Frerichs]

Hey I read it last night! Seek and ye shall find. However, I tried something different with the next part. Knock and the door shall open... It was more like knock and the drawer will open.. Problem was we don't have any former employees that left any of those cables in their drawers.. But thanks mucho for the information in your post of problem solved! I have become freinds with a fellow who just happens to work in our IT department. He has been promoted recently and has remarkable purchasing powers! I handed him the information from your post this morning and he assured me that covert ops would take care of it. Life Is Good!

[rsdoran]

Yeah, its a good idea to get friendly with the IT guy/gal. In my case it happens the IT guy use to have my job. Whats so unique is I know his job as well as he does(I was/am an OEM for computers), he comes to me for info. I give it freely, makes my job easier(when I need a computer related item) and I doubt he will be replaced by anyone any time soon, unless he decides to leave.

[Ken Roach]

I wish there was a message icon for "running around screaming with hair on fire".

The one thing you won't be able to use a USB/RS232 converter with is the 1747-PIC/AIC+ driver in RSLinx. That driver is tricky enough with a classic 16550 serial UART chip, but putting the USB layer and redirector software in the middle makes it impossible.

I have not had a USB/RS232 converter fail to work with DF1 full duplex protocol, and I've used four or five brands; Quatech, Belkin, Keyspan, etc.

You'll find them in retail stores now; I bought six Belkin units from Fry's in a hurry for a Logix 5000 class when I found the rented PCs had no serial ports. Those were a little flimsy, with a too-big transparent plastic shell. The main plus is that they were fun to take apart to examine the FTDI chips inside.

I prefer the one B&B Electronics sells, mostly for it's small size and indestructible potted polyurethane shell.

My best guess with the Micro 984 is that the "real" serial port is a little weak on voltage levels (maybe a power saving thing) and the USB converter is a little more standard !

[Derek Frerichs]

Yeah Ken, I saw the same one a few months back at Fry's. I was on one of my trips to Dallas to face Meca uh, Frys, and I saw them. I was tempted to pick it up but was not sure just how well it would work so I balked. Now that I have my covert op guy in IT things are going to be much better.

I can't thank everyone enough for their input.

Derek

[Peter Nachtwey]

Doesn't the whole world know that Modbus protocol depends on timing (character times) to determine when a packet start and stops?

Doesn't the whole world know that USB/serial adapters buffer characters thereby changing the timing between characters/packets because the USB/serial adapters doesn't know where the packets begin and end?

At least Modicon users should know this.

Obviously the IT guy was LACKING in the 'I' part of IT. I would hold this over his head the next time a decision like this had to be made.

Get a Dell Inspiron 8100. They are great for programming. Inspirons 8100 have 1600x1200 pixel screens, a serial port and Ethernet port.

DF1 works over USB because DF1 does not rely on timing during normal packet transfer. The USB adapeters do slow DF1 down.

We have found that USB/serial adpters slow down PLC serial protocols. Moving window protocols, such as ZMODEM, would not be affected as severely.

[Derek Frerichs]

Well it has been my experience that The Whole World as you say does not apply to IT. In the minds of IT you are in there world and there are no other worlds than IT. If you talk to someone at IT about PLC's most get a very strange look on their face.

The first law of IT is that the perfect network has no users.
Users are stupid and have no reason to request something from them that they don't understand. If they don't understand it, you don't need it. I am fortunate now that I have a friend in IT now that I have lured over to the Dark Side. Boo Haw Haw Haw Haw... Sorry that was my best evil laugh.

Derek

[Rick Densing]

You mean that there are other ways to send data besides ethernet? -IT Guy ;)

[Derek Frerichs]

Rick! There certainly are other ways... There's the European Swallow carrying packets in the coconuts tied to their feet. No, I mean the the South African Swallow. AAAAAAAHHhhhhhhhhhhh....

I wish I were a lumberjack.

[chakorules]

KEN ROACH: I have not had a USB/RS232 converter fail to work with DF1 full duplex protocol, and I've used four or five brands; Quatech, Belkin, Keyspan, etc.

I just wanted to back this up what Ken said. I bought a computer once that did not have any com ports on it externally to install on machine. But it did have USB ports. I purchased a Netgear RS-232 to USB adapator and connected that to a CP3 cable to the front port of a SLC 5/03. I was using DDE in EXCEL to poke and request data from the SLC data tables every 4 seconds. Reading about 15 words of data each wack. The only problem I had with the USB to RS-232 was I had to slow it down to 9600 buad. But after that, it seem to work like a champ. Never had any issues with getting my data into Excel via a DDE link with the NetGear USB adaptors.

Just wanted to share that.

Seems like anytime I have EVER dealt with DF1, either via a cable or modem lines, I've always used 9600 baud by default and always got a good stable connection....

[Ken Roach]

Mike Hendrickson's experience seems to be opposite what we'd expect; his Modicon Micro worked better with a USB adapter than with a regular PC serial port.

Maybe he's using Modbus ASCII format (less dependence on timing) or maybe there's something really, really, wrong with his PC's regular serial port. Or maybe the sun rises in the West where he works.

Thanks, Peter, for pointing out that Modbus RTU with it's 3.5 character timing requirement is not a good candidate for USB transport. The same I know is true for DH-485 and I suspect is true for GE's SNP with it's breakpulse.

I live in an A-B world but I'm about to immerse myself in Prosoft Modbus modules for two weeks. (deep breath.... gluggglug-glug-glug)

[ganutenator]

At my last job, the IT person would actually keep sneaking onto my laptop when I was at lunch or home and remove my administrative rights. It happened so regularly I installed a program to record his passwords when he logged on. He couldn't figure out why I was able to keep changing it back, hee hee. I tried to explain to him over and over again why I needed to be an administrator on my local machine but kept getting the deer stuck in the headlights look. Conversation would go like this:
me "I really need to be able to install and unistall drivers on my machine"
it - "Your not allowed to"
me - "What if I want to reclaim my serial port from RSLinx"
it - "RSWhat? our standard here is ethernet"
me - "the PLC doesn't have ethernet"
it - "PLC?, what's that?"

He wrote me an email at home saying that he installed XP on my laptop.
I wrote back saying something to the effect "I hope to god that you didn't"



I was laid off immediately


hence my newly purchased domain name - www.prousucks.com

[rsdoran]

In my life I have learned a few things.

1. Never share a woman...

2. Never share a laptop....

3. If a company laptop then dont use it for company things like email
etc (unless you travel and use), get a desktop for office/shop.

4. Never leave for IT to get near, they must act important and do
things, usually deragatory to your needs.

5. If the company demands IT oversee a laptop (or its shared and
stays on premises) then have your own laptop
(its less grief overall) and put the software on it. At this time I
do all the real work with my personal laptop...I leave the
advantages to that to your imagination.

6. If you purchase a laptop for yourself to use with plc's verify it
has its own external serial port....be cautious getting Win 2K or
XP

[Eric Nelson]

Time to drag this old thread out of the archives...

The second of my two Toshiba Satellite Pro 435s has finally died. I've borrowed a newer Satellite 3000-S353 that I will probably wind up buying for next to nothing. I refuse to buy a laptop with one of those damned touch pads, so my options are pretty limited... :(

Alas, this laptop has no serial port. As we all know, the USB-serial adapters refuse to work with a 1747-PIC. I tried using my old Socket 2-port PCMCIA-serial adapter (which DOES work with a PIC on my older laptops). The problem is that this newer laptop has a 32-bit cardbus, and the PCMCIA card is 16-bit. IOW, it doesn't work.

Ken had mentioned in another thread about some PCMCIA-serial cards that might work with a PIC. Does anyone here know which ones WILL talk to a PIC. No guessing allowed. I've searched the forum but have only seen words like "might" or "should" work. I'm looking for an answer like "I have a _ _ _ _ _ model _ _ _ _ PCMCIA-serial adapter that I have sucessfully used to connect to a PIC with a _ _ _ _ _ laptop"... :nodi:

I figure that since the PIC is so 'picky', whatever brand DOES work with a PIC should have a pretty good shot at being compatible with other serial devices. I'm looking at the Quatech units, but I'd rather not be the guinea pig... :rolleyes:

Anyone?

-Eric

P.S. FYI, I'm running Win98SE because anything newer sucks... :p

[rsdoran]

Just call me to do the AB stuff, I have a pcmk card and ALL AB cables that work with it. It was easier to get all that then mess with the rest...time is money ya know.

BTW I never found anything that worked with the PIC, it isnt just the connection, its a thing called ACPI (Advanced Configuration and Power Interface). The problem doesnt exist with a serial port because it has its own hardware etc and the PIC was a dos based device DESIGNED for the serial port.

Newer PC's have certain hardware functions controlled by ACPI...its kind of convoluted. ACPI manages power and if a device isnt being used then it turns it off, the problem with that is with a PIC there is a "period of non-activity" that ACPI sees as non use..so turns off the "port". This is the timing issue that people speak of when refering to problems with a PIC on usb or pcmcia.

NOTE: ACPI can be disabled, I am lazy tonite so you will have to search the MS Knowledgebase for that inro.b

[Eric Nelson]

I agree that time is money, but...

Rockwell 1784-PCMK PCMCIA Communications Card US$1845.00
Quatech DSP-100 2 port RS-232 serial PCMCIA card US$199.00
Although the Quatech card may not work, $1646.00 is a B-I-G difference when it's coming out of my own pocket... :(

I can cound on one hand the number of times I've need to use my PIC in the last few years. It's just not cost effective to spend that kind of money on something I use so infrequently. There's even the possibility that I may never need to again. I'd just like to have this capability should the need arise.

For $1845, I can buy a BRAND NEW laptop, WITH a real serial port, AND have money left over... :rolleyes:

beerchug

-Eric

[Eddie Willers]

A-B just announced their (long-overdue, in my humble opinion) 1747-UIC module available for order entry. I won't believe "available" until I see them in stock at my distributor, but I'm getting my order in.

The 1747-UIC is a USB version of the 1770-KF3. It uses the DF1 protcol via the USB port and converts it locally to DH-485 protocol on both RS-232 and RS-485 plugs.

It should be priced just about the same as the 1747-PIC.

[SAK-CO TECH]

I dont know if any of you have heard or used the new 1747UIC cable from AB but, I just purchased one ($ 180.00 my price, $ 280.00 retail).

It is a USB connection to dh485 connection. This is the new replacement for the PIC cable.

I asked my supplier "Does it work?", of course he said "I think so". That being said, I'm going to recieve the cable Monday and test it post haste. I'll keep you all informed on how it goes but if any of you have tried it, please post your findings.

By the way I'm going to test this with XP.

Regards,
Chris

[Eric Nelson]

Thanks Chris (and Eddie!). This looks like a much more reasonable solution!... :thumb:

Be sure to let everyone know if it works for you. If it does, I'll be sure to get one.

I may have to wait a while to get it though. Check out this response from Rockwell's online store when I checked availability of this item.
[attachment]
Note the "Estimated Delivery Date". I don't know that I'll still need it 30 years from now... :p

beerchug

-Eric