Bluetooth & 1200 MicroLogix

[atgroff]

I have 2 overhead cranes with 1200 MicroLogix SLC's in them and would like to communicate with them wirelessly. Trying to work from a ladder on a moving crane is not a good idea, but that is what we are doing right now. I seen the Bluetooth stuff and was wondering if anyone could help me out on what I need & where to get it. I will be using a Toshiba Satellite notebook and it has 2 PCMCIA slots. I have tried going through my local A-B dealer and he did not know what I was talking about, and he did not think it could be done. Needless to say, he was not much help.

Help!

 

[PhilipW]

There are several ways I can think might work leaving aside Bluetooth for the moment.

The best I think is to get a 1761-NET-ENI Ethernet to DF1 bridging module and a standard commercial 802.xx wireless network access point. Both of these then get mounted on the moving crane.

My Toshiba has wireless networking built-in but if yours doesn't then a PCMCIA card for the job is not expensive.

The merit of this method is that it is using very standard off the shelf parts in a very standard manner that is easily setup and understood.

 

[ckchew666]

There are several ways I can think might work leaving aside Bluetooth for the moment.

The best I think is to get a 1761-NET-ENI Ethernet to DF1 bridging module and a standard commercial 802.xx wireless network access point. Both of these then get mounted on the moving crane.

My Toshiba has wireless networking built-in but if yours doesn't then a PCMCIA card for the job is not expensive.

The merit of this method is that it is using very standard off the shelf parts in a very standard manner that is easily setup and understood.

Hi philip,

You've personally tested it and it's working fine with all the WEP or WPA security enable? It sounds interesting to me Would get a set and try to configure them if it's working

Thx.

 

[PhilipW]

Actually no I have not personally setup the exact system described, but just two months ago I was on site at a very large new sawmill project that was fully networked with Ethernet/IP connecting to at least 100 different AB devices, including 6 large ControlLogix system, and more than 60 AB Powerflex VSD's and SS.

On site there were up to five controls engineers all accessing the network exclusively via standard off the shelf wireless access points(WAP) and PCMCIA WAN cards. When I arrived I simply turned on my laptop's internal wireless, configured a new Ethernet/IP driver and within 20 seconds RSLinx had scanned the entire network...very cool. We didn't use any security as the location was sufficiently isolated that anyone not on site would not be able to gain unauthorised access.

I was not involved in setting up any of the WAP's, but I don't recall anyone saying that it was difficult at all. Sorry I don't have more details, maybe someone else has done this hands on and can add more info.

 

[Ken Roach]

Do you have to go online with these controllers with a PC, or do you also have to communicate with a supervisory computer or controller ?

How far do you have to go ? I've seen Bluetooth in 10 meter, 30 meter, and 100 meter power ratings.

Bluetooth/RS232 converters would be more compact than a Net-ENI and an Access Point. But they might not be any cheaper than a spread-spectrum industrial radio.

Very likely what you'd do is put a Bluetooth/RS232 converter at each MicroLogix, then on your PC you would configure the PC's Bluetooth adapter to connect to each of them as a remote COM port.

I have been wanting to try such a thing out but I haven't been able to justify the cost just to satisfy curiousity.

 

[atgroff]

I need to be able to go online with my PC. The cranes are about 20ft in the air and travel about 250ft. The 30 meter range would probably work just fine. Getting around under them is fairly easy. The installation of these cranes left alot to be desired. There are a lot of limit switches and photoeyes that get out of adjustment. Being able to what the PLC is doing from the ground would make my job easier.

 

[dale1627]

I haven't tried it with any AB stuff but I have done it with an AD DL05. Used a wireless access point hooked into the DL05's HO-ECOM and the wireless network card in my Dell's PCMCIA slot. No WEP security setup and didn't try it at any great distance. I didn't do any programming with it, just looked to see if I could find the HO-ECOM. It saw it so I would assume that I could have used the link. Reason I tried it was because I have been putting DL05's with EZ-220P's into our printing presses for data collection. Didn't want to run cat5 to every press but decided it was cheaper and more reliable than wireless. I may play with it some more tomorrow if I have a spare HO-ECOM in the shop.

dale

 

[Ken Roach]

It's the cost of the Net-ENI's and the bulk of a wireless access point and power supply that are making me cringe a little.

I'm interested in the Serial Port Profile (SPP) that is part of the Bluetooth specification. I found some inexpensive Bluetooth adapters from Lumos International that might be worth a look.

 

[ckchew666]

Hi,

I remember we've tried out the RadioLinx in Prosoft office (malaysia), but that pair (transmitter & receiver) cost around RM15K here, abt USD4K! just for a node It has an access point as well, and can connect our standard 802.11 wireless device. It cost a bomb! Reason it's so expensive because it's industrial graded & the signal strength is much stronger + stable than the normal Access Point available off the shelves. Sorry, this application ain't bluetooth, but I think it's even better than bluetooth as not many n/book comes with bluetooth capability at the moment, whereas wifi has becomes another standard in Centrino n/book Correct me if i'm wrong.

 

[Bitmore]

Spread spectrum 900 Mhz. Just Google it!

 

[Ken Roach]

A New Toy !

I was able to justify an inexpensive Bluetooth / RS232 interface as part of a proof-of-concept demo for a customer... new toys !

I found a Bluetooth serial port converter from a U.S. distributor called Lemos International. It took about a week to fill my order and just 2 days to transit the country via UPS. Price was $149 USD.

The unit turns out to be made by a Korean company called Initium. This particular unit part number is the "Promi SD-202" and is a Class 1 Bluetooth device with 63 mW of output power.

You can also buy a Class 2 unit with just 2.5 mW of power; it has a battery inside. The one I have uses a 5V power jack.

The device comes with a little "PromiWIN" utility to set it up. I plugged mine into my laptop's COM1, started up the utility, and easily configured it.

I set it for Mode 3 (discoverable by all Bluetooth devices), 19200 baud (default was 9600), no handshaking (default was h/w handshaking), and set the name of the device to "Wireless PLC". Those were the only changes I made. I left it with no authentication or security enabled.

Next Post: The Hard Part

 

[Ken Roach]

The Hard Part

I already owned a USB/Bluetooth "dongle" for my home PC that allows me to use a Bluetooth headset. I have a Belkin F8T003 unit, with Class 2 power rating.

I am unimpressed with Belkin's software. I find it to be awkward. It tries to look like Windows Explorer, but it's nonintuitive and I get an awful lot of unexplained failures to initialize, or requirements that I start and stop it. This is all with my headset at home; I had not tried it with my RS232 interface.

I would recommend not buying a Belkin Bluetooth interface. My next one will be from Linksys or another vendor. Maybe my next PC will have Bluetooth built in.

The Bluetooth specification provides a profile called "Generic Serial Port", which the SD-202 provides. The "Bluetooth Neighborhood" view discovered the SD-202 under the name "Wireless PLC" and discovered the Generic Serial Port service onboard it.

After a go-around with the Belkin software in which it set up the connection to use "pairing" security (remember I left the device as unsecured), I was able to use the "Quick Connect" function to connect to the "Generic Serial Port" service on the SD-202, and it enumerated as COM14.

I have plugged a LOT of RS-232 interfaces into this computer over the past year, including some USB ones that take over a new COMx number every time you plug them into a new hub port. Other users would probably find this device enumerating as COM3 or COM4.

Next post: Falling off a log

 

[Ken Roach]

Falling off a log

The good news is that RSLinx worked like a champ through this connection.

I opened up RSLinx and created a new "RS-232 DF1 Devices" driver.

When set for COM14, Autoconfigure correctly identified the MicroLogix connected to the SD-202, and set the error checking correctly. It got the data rate wrong, though; it believes it is running at 115200, when of course the SD-202 and the MicroLogix are both set for 19200 baud.

I was able to easily go online with a MicroLogix 1500. Because the SD-202 serial port is pinned as a "DCE" device, I needed to use both a Null Modem adapter and a gender changer to connect it to an ordinary 1761-CBL-PM02 cable.

If this is going to be a permanent installation, you might consider using a MicroLogix/PanelView RS-232 cable, which is already pinned to connect to a "DCE" type port.

The performance over the air was acceptable; timers and ladder logic states update every 200 ms or so. Driver Diagnostics shows about 7.5 packets/second over the Bluetooth connection, versus about 16 packets/second over a hardwired RS-232 connection.

 

[TRACY H]

Hey Ken

We`ve thought about the same bluetooth deal. Will what
you`ve done work with the MicroLogix 1000 also?

 

[Ken Roach]

I happen to have the Bluetooth device plugged into a MicroLogix 1500 right now, but I expect it will work with any controller with an RS-232 port, including the MicroLogix 1000.

I just plugged it directly into the serial port of a 1756-L1 ControlLogix, did a DF1 Autoconfigure, and went online with the Logix.