Carlo Gavazzi Dupline control systems

Has anyone who might be using Dupline products built their own Dupline to serial port interface? www.dupline.com
The data has a 8 millisecond synch pulses and up to 128 pulses every
millisecond there after depending on how many channels are bring used. then it repeats. No other layers of data so far as I have read. Carlo Gavazzi refers to this data stream as Field-/Installationbus
Its serial in nature as only two wires are used, on for data and one for common. The pulses appear to be negative going between 8.2 - 2.2 volts with the active sensor pulling that low voltage to 0.7 volts on a per pulse basis. so if one channel is active only one pulse of that available number of pulses with be going to 0.7 volts.
I have two systems with over 2000 water level sensors attached.I would like to be able to monitor for an intermittent water sensor using a PC that would store when the sensor was active.
I am aware Dupline does make some interface products, but none seem to fit my needs or are configured that I can utilize them.
It never hurts to ask if somebody here has crossed this bridge.
Thanks
Gary Fiber
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Gary, I've used Dupline on many occasions (it's great for remote E/Stop indication) - but in every case we have hard-wired the digital I/O directly to the PLC using multi-point I/O modules. Two main reasons:
1. The interfaces are ridiculously expensive, and 2. Because hardly anyone uses them, support is almost impossible to find..
Because the networks can get extremely complex if you want them to, with Dupline, the KISS Principle definitely applies.
BTW: The only downside to Dupline - it doesn't like lightning surge ;-)
Cameron:-)
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Cameron,
On Mon, 20 Sep 2004 08:44:51 +1000, "Cameron Dorrough"

I do the electrical / electronic work on the WSDOT I-90 floating bridges. I have lots of Dupline as it is the alarm system for the 2130 water sensors on both bridges. One bridge has 18 pontoons with 65 separate water tight cells per pontoon each having a water sensor and the other bridge has 20 pontoons with 48 water tight cells per pontoon also a water sensor per cell. So I have some 128 channel Dupline system on one bridge and a 64 channel Dupline system on the other. The " Local Dupline" is then applied to a bridge Dupline showing a water alarm, smoke, transformer high temp and main breaker fault. The sensors are optical.
Fortunately we do not have much lightning in Seattle.
With all these sensors it would be nice to catch the intermittent one in the pontoon when it is being troublesome. I was thinking of looking at the bit data, counting the bits and having a couple of comparators flag the good bits verses the active sensor and storing that in a computer.
I'll have to look at the PLC module you are referring to.I take it you just bring the 2 wire Dupline signal into that module, no interfaces?
Gary
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What exactly do you mean by "intermittent"/"troublesome"? I'm guessing that the sensors you are using give a digital (on/off) output.. how do you know when one is playing up?
1. The modules I'm thinking of are multi-output Receiver modules, like the GAD1500, but I have never worked on a Dupline system that size (the largest was about 300 I/O) so I'm not sure how practical it would be to have hundreds of these..
2. As far as PLC interface modules go (the "not cheap" option), there is a Devicenet module or a Profibus Module. How do you "capture" the data at the moment? Some sort of datalogger??
3. I wouldn't recommend hooking anything fancy onto the Dupline itself - it is *really* sensitive to surges/shorts/etc - your chances of taking out the Channel Generator is quite high.
Cameron:-)
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On Mon, 20 Sep 2004 15:03:08 +1000, "Cameron Dorrough"

The system is supervised so the water sensors are in conduction, normally closed. when they see water, the sensor opens the circuit to the transmitter causing it to activate that channel.
We have a panel that has 48 lamps on it and when a water sensor is active the lamp lights for the proper water sensor. These lamps are not latched when lighted. The problem arises the water sensors will activate for something more than 4 minutes and less than the time we can get to the pontoon. The bridges are over a mile in length. So we wait until it fails and put up with these intermittent activations. The 4 minutes comes from a timer relay. The 4 minute time runs before the relay activates an auto dialer to call a central office.

I have similar receivers installed. The pontoon transmitters go to 2 AND receivers when activated will turn off the Dupline transmitter causing an alarm at the office end which lights a lamp in the indication panel as to which pontoon is in alarm.

NO datalogger just indication lamps that are lighted with receivers for Channels A1 - A8 // F1 - F8. Once the water sensor clears if it does, these lamps turn off, so the intermittent fault is lost.

I was thinking of a couple of transistor circuits or comparator circuits. I do have an out of circuit test fixture I can try this idea out on first before attaching it to water alarm system. also have a spare channel generator.

Thanks for the advice and conversation.
Gary Fiber
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wrote:

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Have you thought about wiring the receivers to the inputs of a small PLC that has some communications capability (maybe a Mitsubishi FX0 or a Rockwell MicroLogix) and then connect the lamps off the PLC outputs?
This would allow you to ditch the timers and set whatever timeout you wanted in software - and even to flash the lamps in a "not acknowledged" state... Also you can then connect to the PLC using a dial-up modem to find out where the problem is before you even get there.

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If you want to try this, post this question on news://sci.electronics.misc and see if anyone there can help. Sorry I can't - I believe in plugging in "black boxes" and then hassling the manufacturer if it doesn't work. ;-)

A pleasure.. Good luck!
Cameron:-)
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