Water System Control Telmetery

[Robobob]

I have a project for a Municipal water system that is using 900Mhz serial radios to link several sites together for control and SCADA. The radios are obsolete and no longer available also one of the sites is failing. I am looking into other options to replace the radio system. The controllers are SLC 5/03 and they are using DF-1 to the radios. My first thought is to connect the sites over the internet. The area is served by a wireless internet provider that can provide service to all of the sites.
They also will set up a VLAN for the system. I have several options to connect the PLC to the Ethernet VLAN. First is a serial to ethernet converters on all of the DF1 ports. Will this work? The second is replace the SLC 5/03 with Micrologix 1400. Or should we simply replace all of the radios. We do not do this kind of applications very often and I am looking for some direction from some of you who have done more of this kind of applications.Is the internet option a good one? I know this has some security risk and have some ideas on how we will deal with the risks.

Thanks

Bob

 

[Stephen Luft]

Bob,

If you want to remain wireless, then you may want to consider the RM-90 from Westermo. More information is availble through the following link:

http://www.eternity-sales.com/Westermo/Industrialwireless.htm

They also have a 2.4 GHz version as well.

If you want to go wired, we have other options as well:

SHDSL - http://www.eternity-sales.com/westermo/wolverine_shdsl_ethernet.htm

Fiber - http://www.eternity-sales.com/Westermo/fiberchannel.htm

Converters - http://www.eternity-sales.com/Westermo/media_converters.htm

Disclosure - ESI is a Westermo Distributor

Feel free to email me through the link below or pm me through this forum if you have any additional questions or would like to discuss ordering.

 

[Tom Jenkins]

I'm skeptical about getting sufficient range from conventional wireless internet. There are a variety of manufacturers that provide spread spectrum radios for Ethernet and for serial. In most water telemetry applications the data throughput on serial is more than adequate, so I don't see any advantage in going to more complex systems.

Allen Bradley is making the SLC obsolete, but parts and support will be available for many years. Unless the SLC platform isn't adequate, I'd say keep it.

 

[shawn_75]

You already know what it takes to go with a new wireless radio and that it will work. I would do that instead of adding another layer of complexity and the potential problems a third party could introduce. Not to mention the security concerns and now an additional monthly bill.

 

[jkerekes]

Prosoft also makes some nice wireless gear for this type of application.

 

[jgreenewv]

Having installed a telemetry system for a customer using the Internet as the communications medium (city owned the cable system, so we used their cable Internet service) I would say without reservation, buy new radios. You will have much less heartburn in the long run. If your wireless Internet supplier has a backhaul issue, becomes unresponsive to you, or flat out goes out of business, you're up a creek. You will also need to consider communications security, latency, and requirements for additional hardware.

 

[Robobob]

Thanks to all who replied. One of my issues is breakdown of the antenna cables. The cables go to the tops of a couple of water towers. One fails fairly often. Can anyone suggest a SWR test meter that will not break the bank. I will be needing one to trouble shoot the antennas. I am looking at this one, its a bit pricey http://www.atecorp.com/products/bird/sa-6000ex.aspx

 

[jgreenewv]

I had good luck with this one:

http://www.tessco.com/products/displayProductInfo.do?sku=40330&eventGroup=4&eventPage=1

 

[jrwb4gbm]

Snip...
One of my issues is breakdown of the antenna cables. The cables go to the tops of a couple of water towers. One fails fairly often...

Maybe you can get some surplus cable TV trunk line, Along with the matching Pin connectors that adapt directly to PL 259 types. Even though it is 75 ohm, It will work just fine in most all applications.

 

[Bit_Bucket_07]

You're self-sufficient when you're running on your own network. You don't have to worry about your ISP's availability. You're also safer from hackers than you could ever be if you're on a public network.

If you can't get new radios that speak to the DF-1 port on your 5/03s (and I suspect that you can), then you'd need to upgrade to a 5/05 CPU to get a fully functional Ethernet port. If you don't have extensive logic or I/O requirements, then downsizing to the 1400 with Ethernet would make sense. The old RS232 and RS485 serial protocols are losing support.

 

[diat150]

I have a project for a Municipal water system that is using 900Mhz serial radios to link several sites together for control and SCADA. The radios are obsolete and no longer available also one of the sites is failing. I am looking into other options to replace the radio system. The controllers are SLC 5/03 and they are using DF-1 to the radios. My first thought is to connect the sites over the internet. The area is served by a wireless internet provider that can provide service to all of the sites.
They also will set up a VLAN for the system. I have several options to connect the PLC to the Ethernet VLAN. First is a serial to ethernet converters on all of the DF1 ports. Will this work? The second is replace the SLC 5/03 with Micrologix 1400. Or should we simply replace all of the radios. We do not do this kind of applications very often and I am looking for some direction from some of you who have done more of this kind of applications.Is the internet option a good one? I know this has some security risk and have some ideas on how we will deal with the risks.

Thanks

Bob

check out freewave. they have a 900 mhz industrial model that is cheap and dependable.

 

[DwSoFt]

check out freewave. they have a 900 mhz industrial model that is cheap and dependable.

i agree. i have used the freewave radios quite a bit and would reccommend them as well