However, a normal timer cannnot time to 70 hours for the reasons explained above. They key thing to remember is the magic number of +32,767 which is the highest decimal number that a 16 bit word (D register) can hold.Īs most timers in the Mitsubishi world count in tenths of a second, the longest a normal timer can count up to is 32,767 / 10 = 3,276.7 seconds which equals 54.6 minutes, so you can use a normal timer for your 50 minute period (50 x 60 x 10 = 30,000 which is in range) If not, make yourself a small spreadsheet now as it will come in useful :) You may find that the GOT has a scaling function built in - certainly the older Beijers HMIs did - which calculates the gain and offset for you as you enter the bit range and engineering units range.
This means that our ranges are 800-4,000 on older kit, or 2,400 - 12,000 on high res more modern kit. We always set our analogue inputs up to read 0 - 20 mA, even though all our sensors send 4-20 mA signals, the reason being that you can easily see the mA being sent even though it may be below 4 mA. Yours was a very simple example as the start of the line is at (0,0) meaning that C is 0, but in a lot of cases that's not always true. So your equation becomes Hz = 0.0125 x bits. You can now write down two equations, and as there are two unknowns then you can solve. You can write down two point that you know - in your case ( 0,0) and (4000, 50) Where m is the gradient of the line and C is a constant (also knows as the gain and offset)ĭraw a graph with Hz on the y axis and bits on the x axis. I'm obviously missing something and wonder if someone could advise what that is please.īy the solution of simultaneous equations.Įvery straight line has the generic equation y = mx + C
If that is correct, then Rung 4 would not be run during that time and M2701 would be OFF - and yet it is ON, showing that Rung 4 is clearly operational. The top of the graphic shows that scenario and I would have thought that the programme would go through Rung 1 and Rung 2 and then when it gets to Rung 3 it would loop back to Rung 2 and carry on looping until V7 gets to 100. I start the routine with V7 set to a large negative number (-32,000) to give me time to monitor the programme. Rung 4 - Purely there so that I can see if Rung 4 is being run as part of the programme. Rung 3 - If V7 is less than 100, then it should jump to Rung 2 (START_1) Rung 2 - Labelled START_1 and purely adds 1 to V7 (an index register) as long as V7 is less than 100
#GX WORKS 2 SETUP FOR MONITOR ONLY CODE#
Rung 1 - Meaningless code just to have something there For the first time in my career, I find that I'm looking to write "For Next" loops using index registers to solve a problem, but am struggling to make sense of the way these things work.Īs shown on the attached graphic, I have an old FX2N hooked up and the entire ( 4 rung) programme is shown as two screen shots.
0 kommentar(er)
