Post by thread:LonWorks/Echelon (realtime control)

Hi everyone, Let me start out by saying that this PIC list is great in whatever format it takes. My question has to do with LonWorks networks. First let me describe my opportunity. I have designed a timer (based on a Basic Stamp and a PIC16C84) that uses two photoeyes, a solenoid, a light and possibly other things too. All of these devices have to be located about 150 to 1000 feet from my console. The system is portable so I did not want a lot of wires going from the console out to the devices. In my day job, I see a lot of FieldBus, DeviceNet, SDS and things like that. This got me to thinking that I would be smarter to put all of my devices on a bus for 2 reasons: 1 I would not have as many wires to run to the devices and 2 I could expand the number of devices out in the field and not have to change my cabling. Most of the field devices are simple off/on but some have, like a large digit display, will have to receive numbers from the console and display them on 12" tall characters. My questions are: 1. What is the simplest bus to implement? By this I mean, what chips are out there to implement this bus and how difficult is the programming? 2. Does anyone have any experiences with creating devices that sit on a serial bus? Any information anyone has would be greatly appreciated. ~*~*~*~*~*~* Troy Powledge TCo. Systems spam_OUTtpowTakeThisOuTeramp.net *~*~*~*~*~*~ Two rules to live by. #1 Don't sweat the little stuff. #2 Its all little stuff.

At 23:46 06/05/97 -0500, Troy Powledge wrote: >1. What is the simplest bus to implement? By this I mean, what chips are out >there to implement this bus and how difficult is the programming? Probably the simplest (in terms of readily available chips) is RS485. You just put a driver chip (like for RS232 -- the main difference is that you have to control the direction, as it is half-duplex) at your serial ports, and then you use just normal asynchronous communication. You have to invent (or copy) a protocol that allows your master to address his slaves, send some data to them and possibly get something back from them. Gerhard

>First let me describe my opportunity. I have designed a timer (based on a Basic Stamp and a PIC16C84) that uses >two photoeyes, a solenoid, a light and possibly other things too. All of these devices have to be located about 150 to >1000 feet from my console. The system is portable so I did not want a lot of wires going from the console out to the >devices. >1. What is the simplest bus to implement? By this I mean, what chips are out there to implement this bus and how >difficult is the programming? I think I2C is the simplest. It doesn't need any extra hardware like Echelon, CEbus CAN and others. It's not difficult to bit bang - as shown in AN554. It's not as robust as others but is very capable of moving data from one device to another.It is also supported by a lot of manufactures like Microchip, Philips etc. >2. Does anyone have any experiences with creating devices that sit on a serial bus? I've used I2C, CAN and CEbus. I've also been around Echelon. Chris Attachment converted: wonderland:WINMAIL.DAT (????/----) (0000F28C)

My advice is to avoid LonWorks. If you want a serial bus, I think that RS485/422 is very easy to implement. It is no more difficult than RS232. If you decide to use 485, email me and I will tell you all. I have done all the firmware and all the hardware for a RS485 bus type network. Really simple. Email me directly since I am going to drop this mail list. Troy Powledge wrote: > > Hi everyone, > Let me start out by saying that this PIC list is great in whatever format it takes. > My question has to do with LonWorks networks. > First let me describe my opportunity. I have designed a timer (based on a Basic Stamp and a PIC16C84) that uses two photoeyes, a solenoid, a light and possibly other things too. All of these devices have to be located about 150 to 1000 feet from my console. The system is portable so I did not want a lot of wires going from the console out to the devices. > In my day job, I see a lot of FieldBus, DeviceNet, SDS and things like that. This got me to thinking that I would be smarter to put all of my devices on a bus for 2 reasons: 1 I would not have as many wires to run to the devices and 2 I could expand the number of devices out in the field and not have to change my cabling. Most of the field devices are simple off/on but some have, like a large digit display, will have to receive numbers from the console and display them on 12" tall characters. My > > 1. What is the simplest bus to implement? By this I mean, what chips are out there to implement this bus and how difficult is the programming? > > 2. Does anyone have any experiences with creating devices that sit on a serial bus? > > Any information anyone has would be greatly appreciated. > > ~*~*~*~*~*~* > Troy Powledge > TCo. Systems > .....tpowKILLspam@spam@eramp.net > *~*~*~*~*~*~ > Two rules to live by. #1 Don't sweat the little stuff. #2 Its all little stuff.