LonWorks FT-10 Wiring Recommendations

LonWorks FT-10 Wiring Recommendations

Posted by Steve Joanis on May 31, 2012 5:52:25 AM

The standard for Echelon wiring is NEMA Level 4 Cable (NOT to be confused with Category 4). For the TP/FT-10 channel operating in free topology, the maximum length of Level 4 22AWG (0.65mm) cabling is 500 meters (1,640 feet) maximum total wire length (400 meters maximum node-to-node distance). For installations here at ENE systems we do not exceed 1,500 feet total wire length and no more than 750 feet between nodes.

Here are the cables types that we use. We like to use GREEN cable, so that it is easy to find once installed.
Great Lakes Cable
Model ENE70006GN - This is GREEN cable (requires 25,000 foot min. ~$3,500)
Jim Matte 586-977-3945
888-833-4592 Ext. 259

http://greatwire.com/

James_Matte@greatwire.com

Connectair International, Inc.
Model W221P-2001B
You can buy it from Engenuity here:

http://www.opensystemsproducts.com/modern/itemdesc.asp?ic=CAI03-00

Lake Cable from any Lake Cable distributor:
Model PF222C-04LON
Lake Cable:
Phone: +1-773-385-8700

Web: www.lakecable.com

Windy City Wire
2 PAIR LONWORKS:

http://harrier.smartwire.com/ecom/invmainprof.php?item=105600-S

SINGLE PAIR LONWORKS:

http://harrier.smartwire.com/ecom/invmainprof.php?item=105500-S

If you know of a better method, please let me know!

Converting a Binary Output to an Analog Output Using PWM (Pulse Width Modulation)

I recently ran into a situation where I needed an additional analog output on a Schneider Electric IA Series BACnet (MNB300) Controller.

I was able to accomplish this by providing a pulse width modulated output from one of the triac outputs. Essential, a pulse width output communicates an analog number between 0 and 100% by keeping the binary output on for a percentage of some given time base. For example, if your time base is 10 seconds and your binary output is on for 5 seconds, then you would be communicating that you wanted to analog output at 50%.

In this case, I wanted a 2 - 10 volt signal for an actuator. I used a PWA-1A from Kele.com to convert the pulse width modulated binary output from my MNB300 into a 4-20ma signal. Then I simply installed a 500 ohm resistor accross the output to make convert the 4-20ma signal into a 2-10 volt signal.

Schneider's Workplace Tech software makes configuring a binary output as a pulse width modulated output easy by providing a PWM software block that can be used to configure the binary output.

Here is my wiring diagram.

If you know of a better method, please let me know!