programming cable for slc501-503


Thread Starter

M griffin

I have a new laptop without a serial port. I purchased a usb to serial converter which works well with koyo plc's but I can't get the damn thing to work with a slc501 or 503. Rockwell support was no damn help. Anyone else run into this problem? I don't want to have to spend the money on a pcmk card.

James Craver

Note: The standard RS232 cable is 1747-CP3 Pin layout Computer SLC 2 3 3 2 5 5 If the USB to RS232 converter give you a standard RS232 output then this should work. James Craver Rockwell Automation Techsupport

Alan Rimmington

I assume you are using the PIC to interface from the USB RS232 port to the 5/01. The DH485 protocol through an RS232 is a black art if AB are to be believed. If you are running Windows 2000 for instance then the PIC driver will not work, and AB dont look as though they are going to rectify the situation. I assume that either you new laptop is Win2000 or that the driver for the USB RS232 port is getting in the way of the PIC driver. With the 5/03 processor you could try setting port 0 to DF1 (using your desktop?) and then using the DF1 driver, this may work with your USB RS232. Good luck Alan [email protected]
If you'll look up the Koyo cables on the automation direct website you'll notice that the Koyo PLCs all use a straight through cable, ie pin 2 to pin 2, pin 3 to pin 3. The TXD/RXD pin swap (pin 2 to 3 and 3 to 2) must be internal to the Koyo PLC. If your cable works for the Koyo, but not the AB plcs, you are most likely using a straight through cable. To talk to the AB you will have to get a standard RS232 cable with TXD/RXD pins swapped, also sometimes called a modem eliminator cable. You can get it at any computer retailer, or even Walmart for that matter and it will be alot cheaper than a pcmk card that wouldn't work anyways because you would still have the wrong cable.
I'm using the PIC box when trying to communicate with the SLC-501. I think this is my only choice when hooking up to a 501, is it not? I know the PIC box is working because I can communicate with the SLC-501 using my old laptop.

amora fibrianto

is RSLinx recognize USB to serial converter ?? how come a laptop without a serial port ?? doesn't make sense to me......

Larry Lawver

Support couldn't help because there is no help for the situation. It's not a communication problem, it's a hardware problem. In order to keep the promise of not using system resources like interrupts and ports, the USB device tricks applications into thinking they have access to those resources, when they really don't. The PIC driver has to have genuine access to those resources in order to talk though the PIC on DH485. I doubt that any driver rewrite could overcome the timing and control issues. I have spent quite a while trying to find a way around this problem myself, and I now counsel my clients to make certain they purchase notebooks with serial ports on them if they want to continue to use the 1747-PIC. Trading in your new notebook is probably far more cost-effective than upgrading to a PCMK. Parenthetically, remember that the PIC driver will not run under Windows2000, either! It is only supported under Win9x, WinME, and WinNT4. Hope this helps! Larry Lawver Rexel / Central Florida
It's true the 1784-PCMK and 1784-PCM4 cable are pretty expensive to use just to communicate to an old SLC controller. The main cost of the PCMK comes from the proprietary DH+ transceiver, not the RS485 and RS422 transceivers that are included inside for communication to SLC and PLC2 controllers. I have a five-year-old 1784-PCMK/A card. I use it to communicate with PLC-5, SLC-5/04, SLC-5/03, 02, 01, PanelViews, PLC-2/05's and ControlLogix 1756-DHRIO modules in computers running DOS 6.22, Windows 95 (original), Windows NT 4.0, and Windows 2000. For me, it's a good deal. Mr. Griffin, the original poster, already has a PCMK card and should acquire a 1784-PCM4 to communicate with his SLC's. For our recent poster who inherited a used 5/01 controller in Australia, they're a very steep investment. A-B networking equipment tends to cost a more than its consumer grade counterparts because they have to build compatible or identical equipment for 10 to 15 years, make it work under all kinds of operating systems and conditions, and interface with hardware they built 15 years ago. The 1784-PCMK is a good multifunction card whose cost is in line with the high functions it can perform, but it is overkill for communicating to one SLC-500. Do you think that that USB converter will be supported under Whistler or XP? How about DOS ? On the topic of a successor to the 1747-PIC, I am strongly in the camp that says an enterprising outfit could clean up if they built a USB to DH485 converter with onboard timing and token rotation functions and used port redirector software to make it work like a 1747-KE. Even "legacy-free" computers could use it to communicate with old SLC-500 controllers. (Anybody looking for a hobby ?) I was successful in making a Quatech single-channel USB to RS232 converter work with a 1747-PIC and the RSLinx DH485 driver in Windows 95 but cannot make it work in Win98 or 2000 Professional. I have made DF1 protocol run through the interface under all the Quatech-supported operating systems, to PLC-5, SLC-5/03, 1747-KE, MicroLogix and ControlLogix. Your mileage may vary. Ken Roach A-B Seattle [email protected]
Since you mention that you are using 5/01 to 5/03, I am assuming that you are trying to use a PIC converter box to get onto DH-485. To the best of my knowledge, you are "up the creek" trying to do this. The timing issues are so critical on DH-485 that the USB to RS-232 converter is probably causing too much lag. I agree that the price for the PCMK and cable are beyond ridiculous to the point of insulting. $1200 for an RS-485 comm card, and another $200+ for a cable with an RJ-45 connector. Anyone with AB want to try to defend this pricing? If you are networking the PLC's, you might get away with using the AIC+ module. This would connect to the trunk of the network, and offer an RS-232 connector, which would allow you to use DF1 protocol. If you are not planning to network the PLC's, however, this is price prohibitive to set up (AB price prohibitive? There's a surprise...) My best advice would be, in no particular order: 1. Use koyo. 2. Go to a used computer store and buy a laptop with an RS-232 port. If you go this route, save yourself some headache and make sure it is *NOT* windows NT. Since NT has similar problems caused by lag introduced by the operating system. You can get a cheap laptop for under $750, and just dedicate it to the SLC programming. That's still cheaper than any other AB route. --Joe Jansen
Joe--- Too much caffeine today? You got most of the technical details right, but I have to contradict the AIC+ theory. The AIC+ is not a protocol converter, just an isolator/splitter, so the issues of the PIC driver are not changed. By the way, DF1 does work through a USB to serial converter (in my experience), as you surmised. You really can't blame A-B for this, and certainly no one at A-B is seriously expecting PCMK sales as a result of this. This is not a primary use for the PCMK. The best workaround--- using a computer with a real serial port--- is no sale to A-B at all. Hope this helps! Larry Lawver Rexel / Central Florida
Larry Lawver <[email protected]> wrote: >Joe--- > >Too much caffeine today? Yes. >You got most of the technical details right, but I have to contradict >the AIC+ theory. The AIC+ is not a protocol converter, just an >isolator/splitter, so the issues of the PIC driver are not changed. >By the way, DF1 does work through a USB to serial converter (in my >experience), as you surmised. I wasn't sure. My thinking is that the AIC+, being a trunk line device unlike the PIC, may be more forgiving of timing issues. >You really can't blame A-B for this, and certainly no one at A-B is >seriously expecting PCMK sales as a result of this. This is not a >primary use for the PCMK. The best workaround--- using a computer >with a real serial port--- is no sale to A-B at all. I don't blame AB for this problem. Sorry if it seemed that way. I am a fan of DH-485, because of it's compatibility across the SLC platform. If anything, I am upset with MS for obscuring the hardware so far away from the application that it is becoming unreachable. My only gripe with AB on the PCMK is strictly pricing. $1200 is a bit much for what you are getting, considering it amounts to mostly a UART and some support circuitry. Add in the PCMCIA shell, and you get *maybe* $250 in hardware. probably more like $125 in bulk. I guess I just wish the protocol would be opened so that I can buy a regular 232 to 485 converter and run with that. Maybe even throw an Omron onto the DH-485 network :-> >Hope this helps! If I'm learning, it's helping! --Joe Jansen
Thank you for your reply, I tend to agree with the timing issues, for the simple fact that that was my initial problem with the koyos. The difference being Automation Direct did everything to resolve the problem for me. Which involved the engineers of the koyo software. With one change made in a communications protocol file( can't remember what it was exactly) I was up and running with the koyo. AB left me hanging as far as I'm concern. Where is the justice in paying for AB support?


The reason to pay for support is that when they upgrade RSLogix, and make the file format incompatible with the version you have, you get the new version for the cost of the subscription rather than the cost of a new software package.

Plus, when your activation file gets corrupted and you need to get the secret code to let you use the software that you already paid for, you
don't get a bunch of grief.

I have been blessed so far in my life with good tech support from my distributor, therefore my need to call RA support has been minimal. The 2
or 3 times that I have had to, though, the problem has been quite complex, and the support guy usually was unable to help. My distributor and I have been able to come through with proper research however.

You cannot beat a good distributor for tech support. They are usually willing to come to your site and help out. This just isn't true for RA if you are a small customer.

Although I have since moved from the area, my experience with Holt Electric as a distributor in the Milwaukee/Germantown, Wisconsin area were
outstanding. Interesting, considering RA and RS were also located nearby, and were little help when called.

--Joe Jansen
Even tho the link is a little old, I wanted to weigh in on this as well.

As far as I'm concerned the RA support people have been good. I've no problems with them whatsoever (Their response has improved dramatically in the last several years>

I've got a new Toshiba laptop with a USB-serial converter, and it doesn't work with ANY pic driver )or the AIC+, which is the same.

Found a msg. recently on this site which suggested a PCMCIA serial card, which I'm going to try. I've got a older Compaq with a real serial port that works fine, but I hate lugging the darn thing around.

Bottom line... RA and AB are going away from the PIC and don't want to support it anymore. A bad thing in my mind... AB is well known for hardware that works forever and should realize that we're all going to need new laptops as we work in such a harsh environment. (not to mention that it takes forever to start RSLogix and Linx on a 75 mhz. Compaq).

I would suggest to the AB guys that they let go of the "holy grail" DH+ and let some other people develop for it. They, and us, would all be better off in the long run. I'll not buy a PCMK (boy.. have you ever tried setting one of those things up) and work around it whenever I can. Just a lot of unneccessary walking around to plug into various controllers locally.

DH+ is sturdy and sound.. we just need a way to utilze it more effectively. PCMK (at the price) is not the answer.

Just my opinion and probably wrong...

John Kelley
[email protected]