Has anyone used a Cradlepoint/Red Lion cellular modem for remote control panel comms?

An RSSI of -79dbm for 900Mhz radio link is marginal but should be OK. Depends on the radio and speed you need but you should be fine with a Trio JR900. You can lower the JR900 speed down to 64kps to improve the fade margin. A serial TransNet 900 will work down to -95dbm. I have a pair of Phoenix Contact 900Mhz wireless IO modules working reliably at -108dbm.

We did this once with a cellular routers VPNed together. Had a PLC at each end and talked via Modbus TCP/IP to transfer the data.

We used InHand Networks IR6xx routers. Dont remember which specific series right off hand.

Quote: "You could use an FSK modem like others have suggested, but I've started to recommend clients move away from using leased lines here in that manner where possible... its only a matter of time before the Telcos start abandoning the old copper circuits, and this sort of thing won't fly once the area is upgraded to fibre ".
FSK modems DO work on fiber circuits.
I did a lot of work in the 90's replacing these old time pulse systems with FSK modems because the TELCO's were upgrading copper lines to fiber. I used these modems: https://www.miille.com/modems.htm.

TWS said:

Quote: "You could use an FSK modem like others have suggested, but I've started to recommend clients move away from using leased lines here in that manner where possible... its only a matter of time before the Telcos start abandoning the old copper circuits, and this sort of thing won't fly once the area is upgraded to fibre ".
FSK modems DO work on fiber circuits.
I did a lot of work in the 90's replacing these old time pulse systems with FSK modems because the TELCO's were upgrading copper lines to fiber. I used these modems: https://www.miille.com/modems.htm.

Click to expand...

The issue here was more around that the Telcos weren't happy around providing dedicated connections, at least not at similar pricing to the old analog circuits, for one off things like connecting a reservoir to a treatment plant.

In your case, was there still an ONT provided by the Telco which gave you an "analog compatible" line for the FSK modem to connect to? I'm just curious more than anything else.

defcon.klaxon said:

4-20mA loop <snip> Trenching a dedicated fiber optic line would be prohibitively expensive

Click to expand...

I do work at pharma 'campus' that has two water towers.

The utilities guys told me how they handled the need for 4-20ma signal from the remote tower at about 1500 feet distance. Their property is almost flat but they didn't even consider wireless.

They laid direct-burial CAT5 with 2 junction boxes connecting the two 1000 foot lengths. They hired a guy who rented a walk behind gas powered trenching machine who laid the cable 5" underground, and then had the on-site contract plant electrician install and wire a couple NEMA 4 junction boxes. They used two pair for each 'conductor' for the 4-20mA so there wouldn't be wire resistance issue.

Two 1000' CAT5 spools were about $150 ea.
The guy with the trencher was $800 or $900 for the day's work.
On-site contract plant electrician $500 ? (utilities guys did not know what the bill was for the tower job). Electrician provided the material for the junction boxes.

danw said:

They laid direct-burial CAT5 with 2 junction boxes connecting the two 1000 foot lengths. They hired a guy who rented a walk behind gas powered trenching machine who laid the cable 5" underground, and then had the on-site contract plant electrician install and wire a couple NEMA 4 junction boxes. They used two pair for each 'conductor' for the 4-20mA so there wouldn't be wire resistance issue.

Click to expand...

If we tried to pull something like this, we'd get absolutely crushed hahaha. The treatment plant in question is on federal land, a National Recreation Area specifically. You can only imagine the red tape we have to go through out there.

Saffa said:

Whilst that path is definitely obstructed, I'd just give it a whirl and use the packet transmit test function in the trio JR900s to see how many dropped packets you get with say, 10,000 packets.

The path study shows -79dBm receive signal - I know that's with the high antennas on both ends, but that is plenty of fade margin from the Trio receiver minimum RSSI of -120dBm (from memory).

If you get less than -100dBm both ends, and better than 99% success rate on the packet test, I'd be happy that the link should be reliable enough for messaging one level reading from tank to plant.

I'd be happy to run another simulation for you if you want to pm me the coordinates, using a more achievable antenna pole height.

You could use an FSK modem like others have suggested, but I've started to recommend clients move away from using leased lines here in that manner where possible... its only a matter of time before the Telcos start abandoning the old copper circuits, and this sort of thing won't fly once the area is upgraded to fibre (as is happening reasonably quickly here)

Click to expand...

Thanks for the offer, I'll PM you the lat/longs. Yeah speed is NOT important here, we're literally talking a single analog input and maybe a few discretes like power/ups status and failures.

KirkC said:

An RSSI of -79dbm for 900Mhz radio link is marginal but should be OK. Depends on the radio and speed you need but you should be fine with a Trio JR900. You can lower the JR900 speed down to 64kps to improve the fade margin. A serial TransNet 900 will work down to -95dbm. I have a pair of Phoenix Contact 900Mhz wireless IO modules working reliably at -108dbm.

Click to expand...

Thanks for the info, good to know. As I've said in other replies, data speed is not important, it's just a single analog input with a few discretes.

danw said:

I do work at pharma 'campus' that has two water towers.

The utilities guys told me how they handled the need for 4-20ma signal from the remote tower at about 1500 feet distance. Their property is almost flat but they didn't even consider wireless.

They laid direct-burial CAT5 with 2 junction boxes connecting the two 1000 foot lengths. They hired a guy who rented a walk behind gas powered trenching machine who laid the cable 5" underground, and then had the on-site contract plant electrician install and wire a couple NEMA 4 junction boxes. They used two pair for each 'conductor' for the 4-20mA so there wouldn't be wire resistance issue.

Two 1000' CAT5 spools were about $150 ea.
The guy with the trencher was $800 or $900 for the day's work.
On-site contract plant electrician $500 ? (utilities guys did not know what the bill was for the tower job). Electrician provided the material for the junction boxes.

Click to expand...

That's a reasonable solution on a site where all the property is yours, but I imagine in the OP's case the land between the reservoir and the plant won't belong to the utility. Which means you may need to get easements, or re-route it along road reserve / public land. That then opens up a whole new kettle of fish, for traffic management, other service locates, Codes of Practice for installation in road reserves (maybe not a thing over there, but here we would have to install in a suitably coloured duct, minimum clearances from power, water, phone etc).

For a brand new installation where they're laying the pipe between the plant and the reservoir, it would be a small additional cost to add a duct with pull pits every 100m / change in direction, but doing so afterwards is probably always going to be more expensive than radio, if done properly.

In the last 10 years I have had to install at least half a dozen radio links in a hurry, because of badly laid cables failing, and being impossible to replace / repair due to how or where they were installed. Maybe its because I'm a radio guy, buy I feel a lot more confident going to a comms fault situation where there's radio, than one where there's a big long cable which no one knows the route of.

Saffa said:

Actually, thinking about that... does the site have a power source currently, or was this a loop powered level sensor?

Click to expand...

Loop powered. We'd have to put in a control panel and get PG&E to run power to it, though there is a pole pretty close so it wouldn't be a disaster. Or we could do solar, I have a client that has a solar tank level with radio and even during winter it's reliable.

chelton said:

If terrain permits, could you put in a repeater station that both sites have a more line of site path to?

Click to expand...

Time for a few Pringles Cantennas!

defcon.klaxon said:

Loop powered. We'd have to put in a control panel and get PG&E to run power to it, though there is a pole pretty close so it wouldn't be a disaster. Or we could do solar, I have a client that has a solar tank level with radio and even during winter it's reliable.

Click to expand...

I've heard good reports about these although I have no first hand experience:
https://oleumtech.com/oleumtech-products/wireless-liquid-level-sensor-tank-monitoring