Remote controls

A client of mine asked me for some suggestions about automating his remote pumping stations.

He's got 4 pumping stations. All have stand alone hardwire pump starters. Basicaly they are a 1 motor starter panel with 2 push buttons (Start/Stop) each.

Hes would like to automate this.

The central bigger system is where we will install the main PLC.

The next pump is 6 miles away.
The next pump is 300 yards farther.
The next pump is 300 yards farther.


We have dedicated phone line between them all.

What would you suggest could be a good simple way to unite them in a control system.

I have some ideas but am fishing for more and maybee some I have not tought of.

Tanck'yall

When you say you hav dedicated phone lines are they dial lines or is it dry pair"no talk battery" Also what type of PLCs are you using?

Wow..6 miles, that definitely eliminates a serial connection.

The 6 mile pump and the 2 pumps 300 yards (1800 feet or 270 meters) could easily be networked using some form of RS485(DH485), Profibus, Modbus or DeviceNet etc). I would think maybe a small plc to act as an intermediary/connection device with some form of remote I/O.

This is the part I dont have enough experience with so am just throwing out ideas.

The MAIN BIG system where PLC is located would be hardwired...I assume.

The specifics I believe would involve what brand of plc you use, I know you are familiar with and use AB so thats why I put in DH485. AB is also the creator of DeviceNet (it is CAN tho) so they have probably the easiest DNET system to work with. They also offer a multitude of modem options.

I am thinking along the lines of MicroLogixs since there shouldnt be that big of an I/O count...maybe a 1500 (or a small SLC) as the MAIN plc with the 6 mile pump having another 1500 (maybe smaller) with remote I/O or connected by DNET, Profibus etc...maybe each pump having a 1000 to 1500...networked to the 6 miler than by modem networked to MAIN.

Actually I like the idea of the 6 miler and the 300 yard each have their own PLC networked together, then modem to connect MAIN to that network.

Should be a decent paying job..running comm wire over 600 yards, probably underground...or were you thinking of using RF?

I am just throwing out ideas....

Try to go with modem, not phone modem (dial up), line modem .

-----RS232----------------------------6 mile------------------RS232
PLC ------Modem____________________________________Modem----PLC

I hope I explain it well.

When I will be in office I will try to get more info.

Pierre


Try this site they have some nice things far as I saw they can handle

communication up to 25KM (15mile).

WWW.westermo.se

Please up date us.

I am working with my local electric utility doing relay coordination and monitoring using spread spectrum radio. We did not buy the radios but I will try to find out what they used. Basically we hit a multiplexor on each end and the radios are in the middle. The radios are line of sight and we will be talking about 3 miles. I dont think six miles would be a problem. Also about 10 years ago we did a pumping system using radios but had to have an FCC license for the radios.

Pierre:

Check out the SINAUT line from Siemens. It works with the S7 PLCs and is designed for the application you're looking at.

I have used both MDS and ProSoft spread spectrum ethernet radios in open pit mines, with A-B PLCs. Was able to test the signal strength before committing to the radios.

Less expensive than copper or fiber after just a km or so. Plus, in mining we often do not have an easy path between equipment to install cable. Cable will just get dug up, or too expensive to trench in solid rock.

Hello Pierre,

- As previously reported, modems could be a good choice since you graft small PLC on sites. By using your wires as "leased lines" or dedicated lines in transparent mode, there are no limits to your network... at low speed. But 300 bps should be sufficient in this case. Have a look on Westermo's ?

OR

- You could use some basic, robust and low cost networked I/O called "Dupline". The name comes from Electromatic, now in Carlo Gavazzi Group. See this link : https://www.gavazzionline.com/duplineprod.htm. Plug I/Os on industrial sockets, and choose wich input group (site A) has to be duplicated to one or several output group(s) on other site(s). Useful and very well known in water treatment or more agricultural fields. Analog I/O are also available. Can be interfaced to serial networks.

Have a nice day.

Laurent

Laurent - Yap, Dupline was my choice for the interconnection with the 3 renmote station BUT, it's not an option. Unfortunatly my client put a stop to using Dupline. Politics Ya know!

bwheat - We have looked at some RF Spread Spectrum Ethernet Modems (our remote devices have Ethernet ports) but since this is at a very remote location, we cannot test the stability of the comunication and cannot take the risk of being in a situation where on commissionning we don't have good com.(Darn its a 10 hour drive just to get there )

What seems to be left to us is an ethernet modem on the lease line. The problem is my bad hunderstanding of what exactly a lease line is.

I have done it in the past but it was some short distances (less than 1 km) between plants downtown. Sort'a from one street to another close by.

In this case, will the lease line be only the copper wires or does it have full phone system amplifiers and all. JasonG - you are wright on the button.

I do not have the infos on this. Perhaps some can shed a little light on this .Please

We are tincking of using Nematron Pointe Controler with an ethernet modem setup.

ArikBY - Nice stuff tancks , I looked at it last night. Do you have personal experience with this equipment or did you google the Web? (anybody could do that)

What distance did you get, do you have stats on com errors and such?

Old Timer and Ron - Sorry but on this one I get to call the shot on which brand of controls we will purchase and franckly AB is a joke.
Read MicroLogixs has NO ONLINE EDIT bonkhead

This is as unbeleivable as Mitsubishi's F serie which has no Ethernet module

As many have experienced in the past, the design of a system outputs an evaluation of the cost and time factor. One thing that can really $crew-up ones schedule is a modem network. This is why we may try an ethernet line-modem.
RGB - As much as I like Siemens product, they are not an option (my competition uses it )

So here's how it looks.

• Nematron Pointe Controler at all pump stations
• Ethernet Line modems between the Main and first remote node
• Ethernet line-modems between the 3 remote nodes

Am I way in left field or not

I have used Schneider Electric's Momentum product communicating Modbus over spread spectrum radios from Data-Linc (http://www.data-linc.com/). I know they offer ethernet and leased-line modems as well.

Check out www.controlmicrosystems.com.
They have wireless PLC's

Mickey

Hi Pierre

For applications like this we are using either private-line modems from Westermo or Ritex, or radio modems with RS232/RS485 interface.

Check the "Line Sharing Modems" at Westermo (like LD-01)

http://www.westermo.com/Resource.phx/content/products/short-haul-modems/short-haul-modems.htx

Each modem is a repeater, so there can be up to 18 km between each modem. (modems that is not by-passed)

Check also Ritex: http://www.ritex.se

"Linesplitter". E.g LD-4. Similar as Westermo. Up to 21 km between each modem.


Those privateline modems are only an extension of your "cable".


Check also radio modems with RS232/RS485 interfaces.
For example: http://www.satel.fi/bb/home.nsf/pages/Satelline or http://www.elpro.com.au/405/405_2.htm


Regards

Karl Egil Liaset

If you have found that the lines are dry pairs "no voltage on them" you can use simple short haul modems that you can get in any flavor you like "RS-232 422 485" I have hundreds of them in use at a large brewery and have never had a problem with them. If you are going to use 485 you will need 2 pairs for xmit and rcv. Any questions let me know

Hi Pierre,

a) On point-to-point and very long lines (your line can be a single pair of copper wires), modems offer an affordable interface for serial ports, and allow your network to be used as a RS232 link on table. If it runs on table, it will run like that, with a limit : the transmission speed to be adjusted. But it's transparent and so simple !

Notice : If you didn't select your wires, you can't perfectly know before testing what transfer rate level is usable. So test it ! (Yes, people with phones, talky-walky, and go for 300, OK?, so go for 600... and so on). Anyway, with long lines, a low speed only should be used (say up to 1200, what would be very nice).

So here is my question : why do you plan to work with Ethernet products ??

b) For your intermediate station you may create a "node". Don't create this node (T branch) on the line side between modems, but on serial port side only. Always prefer this method, using modems as amplifiers :

Contr1--modem ----- modem--T/Contr2--modem ----- modem-- Contr3

c) If you have some sense of humor, you could get technical results as needed with a combination of Mitsubishi PLC and Matsu$hita modem (FP-modem) and Ethernet-to-serial converter (FP-Web server). Each module as big as matchbox, rail-mounted, 30mm thick. See http://www.aromat.com/acsd/product/plc/fp0/comm/fp_web.html. I've deeply experienced those solutions. On local Ethernet (around 120m cat5), the ether-to-serial converter "outputs" 115kbps. But don't expect your modems to deliver those rates on long lines, and please, test the limit !

I've got a great experience with modems and such network architectures (built systems up to 30000 I/O points mixing PLC, pretty simple stations from 2 to 50 I/Os and many other systems on the same base plus dial-up for "safety mode", interfaced them to high-speed networks). Don't hesitate to send a message on my personal mailbox (see profile). We can perhaps get in touch for further projects or in order to extend this discussion in french... and then continue here.

Laurent