65 ARDUINO uPCS


- c - Indicator points
and also 2 analog indicators build in, with PV lolo lo hi hihi alarm, what later can be used for PID controller interlocking.

as usual in PLC programmable logic controller and DCS distributed control systems the controller only works with analog values in 0.0 .. 100.0 ( %), one decimal with the 10bit resolution.
while on the visualization level also need to configure x to Y low and high range and a engineering unit (like 200 .. 2000 L/min )
i will implement that into the processing ( operation ) part of that project later,
in the USB terminal LOG that is optional ( see tuning ), if enabled it works on the PV indication, and
also for SP indication and RSP setpoint input! but without changing the control code/values.

Also on the hardware level some adaption is needed, industrial thinking of analog values is 4 .. 20mA. ( at 24VDC supply) by 2 or 3 wire type sensors, normally closed the loop by a 250ohm measuring resistor ( or even 2 for a second safety limit monitoring circuitry ) what is giving 1 .. 5 V to differential input of a AD.
But even i work with it 20 years i do not know about a IC.. to handle that part in a sensor.
its just to tell you that here with our 0 .. 3.3V AD inputs and our 0.55 .. 2.75V DAC outputs
we might need electronic what could cost more as our analog I/O cpu "DUE" to be compatible
to industrial standard. But definitely we must understand about that LIVE ZERO / broken wire detection / thinking.
here how the PV input now look like:
input mapped hwinlo / hwinhi to 0.0 / 100.0 ( and numeric filtered )
( it may not be limited! in case of a LIVE ZERO signal we get a -PV on broken wire,
and a PV LOLO alarm can bring the PID control to a safe interlock mode... )

pid->PV = pid->PV * pid->PVfil0 + map(analogRead(pid->PVchannel),pid->hwinlo,pid->hwinhi,0,10000)/100.0 * pid->PVfil1;
// expect 3.3V >AD> 1023 = hwinhi, to make 100.0 recursive digital filtered PID PV

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for the IDE,
27.1.2014 i download the nightly build ( 1.5.6 beta ) and upload my program,
and when i started the terminal it shows the first line ( send from arduino DUE)
and stopped with error.
Exception in thread "EventThread COM12" java.lang.NullPointerException
at processing.app.Serial.serialEvent(Serial.java:176)
at jssc.SerialPort$EventThread.run(SerialPort.java:1096)
back to 1.5.5. r2 ?fix? ok

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