Posted ByLeon on January 16, 2002 at 01:23:08:
In Reply to: Re: Remote power on/off posted byKen Talley on January 15, 2002 at 22:44:14:
If the battery is not affected by the engine starting process than you will have no problem. You can turn off the power supply to the two PLCs by a master switch. But if you want the controller to do the job then one of the controller can turn off the other, saving half the power.
When a PLC is not driving a load, it draws about 0.15A only, which shouldn't be too much of a problem if you have lead acid battery that are regularly recharged by the vehicles' dynamo.
: The system I am designing is a piece of road construction equipment. The reason for the master slave is to avoid 40+ hard wires routed from the cab of a truck to the rear. The reason I want to power on and off the unit is that I do not see a reason to "burn a candle when the sun is out," so to speak. Do you think it would be OK to leave the PLC's with power on all the time? The power source is from an isolated battery used strictly for the ECM on the truck, it does feed power to the starter when it is started, there are another bank of batteries for that.
: Thanks,
: Ken
: : I guess not. If the PLC turn on a relay to trip its own power, then when its power goes off, the relay will be released the the power returns. Why do you want it that way?
: : : Leon,
: : : Is there a way to remotely power on/off the T100MD1616+ using one of it's IO's?