"Remote" Communications With SLC-500

[Jack]

Manufacturing industrial PLC based equipment, our customers are all over the US. It would be economical for us to send our customer equipment he could connect to his PLC and communicate with us via cell phone. Using the Allen Bradley SLC-500, does anyone know if the equipment is available for remote communications described above? We would want to be "on-line" with the PLC via the cell phone. Our service techs have wireless internet access via the cell now but the idea is not to send a tech 2000 miles to read the status files. Any ideas?

Thanks

 

[Ken Roach]

Questions for the querent

Is the idea for you to ship a box with a cell phone and a serial cable to the customer so that he can plug it in, turn it on, and you can go directly online from a technician's laptop using cell phones on each end ?

Or are you looking to have the customer connect some other way, like a land line or through his own internal Internet gateway ?

And which model of SLC-500 controller are you looking for ? Is the RS-232 DF1 port available on an SLC-5/03, /04, or /05 controller ?

Which cell provider are you using now, and are you directly connected to their data network ?

 

[Sysop]

Why not using a Modem hookup to the serial port of the Slc5/03, 5/04 or 5/05 ?

You'll be able to call from anywere over the world and then b e able to do some troubleshooting.

See the 9300 RADKIT from AB, they are already setup and tested so no engineering to do ...

 

[Jack]

The 9300 Radkit sounds promising, provided I could use it through a cell phone. Has anyone used this device with a cell phone.

Yes, the idea is to send a box of equipment (at this time, I am trying to find out what equipment) to the customer, have him connect it to the Processor (usually a 5/03), connect a cell phone and be able to monitor and change settings and programs from the desktop back in the shop. I stress the cell phone since most of our applications are far removed from a landline.

 

[Xian]

I would have to agree with the others in that it would be much easier to use a land line, or if possible ethernet (I haven't used a SLC in a while so I don't know if they support enet onboard). There are some interesting ethernet to RS232 modules out there as well. Presumably you could also rig up a WAN if the plant has the capability.

Another thing to consider is the reliability of cell phones. I have found that in most industrial environments your signal will not be strong. Losing the connection in mid modification would not be a good thing, no?

 

[Ken Roach]

Start researching your cell providers' modem/data offerings.

Using a modem + a cell phone isn't likely necessary; the cell phone will be acting as a modem, providing an RS-232 plug to the controller, not an analog RJ11 jack.

Find out if your cell provider has a data-only mode. Motorola used to have this; you dialled "*DATA" and were connected to their data network so it didn't try to do voice compression on the info coming from your phone.

I've heard good things about Sprint's PCS Vision system; those picturephones are riding on top of a decent digital wireless data system that's optimized for data packets, not voice throughput. I have a customer who uses those phones for wireless Internet access as you do, and claims regular connections at 56,000 kbps.

What you won't hear from A-B is "sure, that'll work with cell phones". There are hundreds of cell models and dozens of suppliers of service and there's no way for Rockwell to investigate and troubleshoot all of them. At the very least be ready to use configuration scripts (maybe the phones use the AT command set !?) on each side to set up the data rate and compression mechanisms so that your PC's serial port and RSLinx get their packets through in the right sequence to the DF1 port on the SLC-5/03.

AT&T also brags about their embedded data offerings, though those may have been ditched when they discontinued the fixed wireless business a few months ago. The wireless phone business moves even faster than consumer PCs!

 

[Kidblue]

We've set up several AB's around the UK very successfully (ML1500 + SLC503/4's) using a GSM modem. We've used Westermo and recently tried the Siemens T35. They just plug straight into your RS232 port. A couple of our networks over here supply 'Data only' Sim cards, which are ideal for this application.

Utilising the ML1500's Data logging facility we can create a very inexpensive remote data logger.

Rob.

 

[Joe_WaZoo]

I hope you guys don't mind if I resurrect this old thread. I am searching for previous posts to my questions. I have a customer who would like to be able to use a Cell Modem connection to his AB ControlLogix PLC. The units are mounted on mobile trucks and they sometimes need access to the logic to determine what is causing the machine fault. I tried this idea with the new GPRS Modem card for the Red Lion DataStation Plus and it worked great to let me see the HMI side of things. But when I did the Pass-Through comms, which works great everytime on a landline based connection, RS_Linx would fail just about when I was ready to completely go online with the PLC. Maybe a timing thing but I don't believe the Cell card for the Red Lion DSP was designed for this type of application anyway. But it worked great for remote HMI access.

Has anyone used these Westermo devices to give you remote access to the Allen Bradley PLC's? Ken maybe you can suggest something I can pass on to the customer.

Thanks,
Joe_WaZoo

 

[JesperMP]

Has anyone used these Westermo devices to give you remote access to the Allen Bradley PLC's?

Yes. And it was from Denmark to Mexico to Westermo Modem to KF2 to DH+ to PLC5.
It actually worked but was a bit slow because of the KF2.

Biggest problem was that it was a shared telephone line, so when I tried to go online 90% of the time some person would pick up the phone and I could hear "Hola ? .... HOLA ? ..................... IDIOTAS ! *click* .........."

 

[Joe_WaZoo]

Jesper,

Thanks for the comments. I guess I should clarify more. This customer would like to connect over the GPRS Cell Modem type of connection where there would not be a telephone line, but rather cell phone access via the CIM card in the modem. I have the AT&T Data Plan working with my modem and it does the trick fine for the HMI access. But a bit slow for the RS_Linx to synchronize. I was going to call Westermo but they are in Sweden. Maybe I should try to send them an e-mail with my question.

Thanks,
Joe_WaZoo

 

[BTalbot]

Joe,
Have you looked into Moxa, I have not done any thing with their cellular products but it looks like it might have a shot of doing what you need.
http://www.moxa.com/product/GPRS_Modems.htm

 

[Kidblue]

Joe,

Firstly, Westermo are Swedish, but have representation all over (i have used Westermo UK many times).
Secondly, you should easily find a suitable GSM/GPRS modem to achieve what you want to do.

I have never used them to connect to CLX PLCs but i know the principle is the same (i do know colleagues that have done it).

We have connected the ML1100/1200/1500s and the SLC 5-03/04/05 all using DF1 protocol (if it helps, i can post a couple of screen shots).

We normally use the Siemens TC35 modem (purely because it's almost a third the cost of the Westermos). Again, it is relatively straight fwd to configure (baud rate, parity etc) and setting the correct DTE/DCE mode...

You then require the DATA number for the proposed SIM card in the modem (NOT the voice number). This will then be used in RSLinx (via the 'modem dialer' settings) and really that's (pretty much) all there is to it!

Hope this helps!


Rob

 

[BTalbot]

Joe,
Any sucess yet?

 

[Joe_WaZoo]

No I have not had any luck. I thought I had sent an e-mail to Westermo people but can't find it. I inquired with the MOXA guy and they have talked some but I don't know if they understand what I am trying to do. Red Lion did change their code for their GPRS program but I have not had a chance to try it with their card. I just sent a note to the MOXA guy looking for a live demo. I will try to do the same with a local Westermo guy as well.

Thanks,
Joe_WaZoo

 

[diat150]

how about one of these digi's?
http://www.digi.com/products/cellulargateways/digiconnectwanfamilydocs.jsp