PLC TO PLC communication VIA GSM/GPRS or RADIO

[KENNEDY WESONGA]

I have a water treatment plant situated roughly 10-15 KM from The Pumping Station.Would like to have one V570 Running the pumping Station while a more powerful Maybe V1020 can run the Treatment plant.

I need to relay Analog and digital signals between the Two stations for control.I have Have two options for communication.

1. Line of sight Radio using free spectrum and Ethernet communication.
2.  GSM/GPRS

Kindly assist on how the two would be implemented

[Joe Tauser]

The V570 and the V1040 have the same processor - neither is more "powerful".   The V1040 just has a bigger display.

Solution 1 would be most probably implemented using Modbus.  Need brands and part numbers of radios to determine whether serial or TCP would be used.

Solution 2 would use two cell modems and GPRS function blocks for sending information.  Where you are located in the world would determine which modems to use.

If you're looking for someone to pick out all the part numbers you need to bring a system integrator in.

 

Joe T.

 

 

[KENNEDY WESONGA]

Hi Joe,

 

Thanks for the response,I am a system integrator but have been using Siemens for all my projects.However i would like to use unitronics on this one because of cost,have gone through the Visilogic software and looks quite user friendly.Have already purchased V570PLC and enfora modems  and done almost all functions except communication.

Kindly recommend for Me the Hardware for the RADIO comms using 2.4GHz  as a look at the programming bit.

KENNEDY

[Joe Tauser]

 

On 3/9/2018 at 9:20 AM, KENNEDY WESONGA said:

Have already purchased V570PLC and enfora modems

You're not being clear in your request.  Do you already have cell modems installed?   What is the exact model number and preferred data transmission method?  GPRS?

You didn't say what part of the world you're in. 

As for your 2.4 GHz request, are you taking about an internal WiFi signal or a cellular signal?

If you're in the US, I wouldn't have gotten Enfora modems.  I much prefer Sierra RV50's.  They are more expensive up front, but they give you a real Ethernet connection to the PLC just like it's on a local network.

Joe T.

[hotwires]

Kenwood NX-700 or NX-800 VHF/UHF radio transceivers have integrated RS-232 modems with a max speed of 9600 baud. I know of two water treatment applications using these radios with Unitronics Vision OPLC's communicating via MODBUS, the longest distance is 10 statute miles (about 15 kilometers). If you're in a non line of sight, long distance situation these radios can transmit as much as 50W/35W RF power and get the job done. If you have line of sight then the wireless ethernet or RS-232/RS-485 bridges would work at a lower cost. PLEASE REMEMBER TO TAKE THE FRESNEL ZONE INTO ACCOUNT in your path study if you are considering 900 MHz or above. Short of having 100' of tower elevation for yagi or parabolic antennas at each end of the link, I have some doubts. The Kenwood radios do require an FCC radio frequency license. Real world application has proven to me they work excellent for low speed, long distance data communication. No monthly fees as would apply with cellular. Probably less RF interference as can be seen in unlicensed 900, 2400, and 5800 MHz bands.

 Cellular is subject to outages, if not on the same cell tower a fiber optic cable cut could leave you down. The WiFi band stuff...can be an RF jungle out there. Police, fire, and EMS use VHF/UHF land mobile radio for their primary communication for a reason. How mission critical is your control link? The constant (and worst) enemy of all things RF is ice on the antennas. I've seen UHF yagis in power company SCADA use fiberglass radomes over the elements. 

[Joe Tauser]

These look like they could do the job with the proper antennas (if you're in the US or Canada)-

https://www.digi.com/products/xbee-rf-solutions/boxed-rf-modems-adapters/xpress

2.4 GHz doesn't work well over long distance - 900 MHz is better.

Joe T.