Where Is Eric Nelson When You Need Him?

[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]

your suposed to be-friend them? now you tell me

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]

I Didn't Follow Ron's "Rule #6"...

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...

Anyone?

-Eric

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

 

[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...

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]

New AB product

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!...

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...

beerchug

-Eric