Delay between two PLCBUS orders

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Delay between two PLCBUS orders

Postby vdoucet » Thu Dec 16, 2010 8:48 pm

Hi,
I'm using Domotiga (I recently switched from MisterHouse to Domotiga), Oregon probes and PLCBUS material to pilot my electrical heating.
Switching on and off the heaters is based on conditions (temperature in the room, time of the day, day of the week ...) and is triggered every 5 min with a crontab.
My code seems to be running smoothly when piloting a single heater but I'm having troubles when two are running ... I mean the trigger remains the same and two orders can be sent to two switches almost simultaneously (I doubt the software takes more than a few ms to calculate conditions ...). The result is that the soft beleives the switch is off while it is in fact on (and vice versa).
With your experience, is that a PLCBUS issue (in which case I will try offsetting the triggers or ask RDNZL to add a delay loop in the soft (if possible)) or a software issue.
What would be the minimum delay between two orders ? 1 second ?
My PLCBUS equipment is : PLC1141 ; 2x modules DIN 4 loads PLC2268HX2 ; 2x micromodules PLC2267
Ubuntu 10.10 + Domotiga 0.1.194 + Gambas 2.21
Interface PLCBUS II-T PLC1141 G+ (USB) ; 2x PLCBUS2-R PLC2268HX2 ; 2x PLCBUS II-R PLC2267-H ; 1x PLCBUS II-R PLC2267-K
Oregon Scientific (7x THN132ES, 3x THGN132ES, 1x PCR800)
RFXCOM (USB ; firmware 20)
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Re: Delay between two PLCBUS orders

Postby Digit » Thu Dec 16, 2010 9:24 pm

Hmm, let's see if I understand what your problem is. When you say that the software thinks a switch is off while it is in fact on, you could think that's a software issue. Is it? I don't think so. Is it a hardware issue? I don't think so either! :) So I don't really understand what you are seeing.

When you say "thinks a switch is off while it is in fact on", you must be talking about the very short period where the "on" command has been sent to the switch, but the ACK (acknowledge, in other words the response that the switch has indeed switched on) hasn't arrived yet and hence the status of the switch in software remains off (until that ACK has been processed). This incoming ACK is received within a tenth of a second (IIRC) after the outgoing "on" command, so that's a very small time frame, where the "software status" of the switch can be different from the physical status.
Is this the situation you describe or am i missing something?
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Re: Delay between two PLCBUS orders

Postby vdoucet » Thu Dec 16, 2010 11:36 pm

Thanks Digit.
I think I posted this message to fast. But you opened my eyes on several points ...
I think it is linked to another issue I reported in the Domotiga forum : viewtopic.php?f=38&t=5735
The feedback from the receivers is not correct. I don't know yet why.
Ubuntu 10.10 + Domotiga 0.1.194 + Gambas 2.21
Interface PLCBUS II-T PLC1141 G+ (USB) ; 2x PLCBUS2-R PLC2268HX2 ; 2x PLCBUS II-R PLC2267-H ; 1x PLCBUS II-R PLC2267-K
Oregon Scientific (7x THN132ES, 3x THGN132ES, 1x PCR800)
RFXCOM (USB ; firmware 20)
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vdoucet
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Location: Pau, France

Re: Delay between two PLCBUS orders

Postby Digit » Fri Dec 17, 2010 12:10 am

OK, I read that topic, but didn't "link" it to you :)
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