digiwolff

Hey guys I am swapping out an old ML1500 with a SLC 5/05. I have rewrote the program because i dont have a copy of the project file from the ML1500, only raw later. I can however take the PID parameters which were supposedly tuned with expertune at some point, and enter them into the parameters for my new PID. My question is, does anyone know if the transferred parameters will work the same as they did on the old PLC? Or does it need to be retuned?

i determined there was no current by putting a multimeter in the middle of the signal wires. the other channels on the card were also messing up, it turned out to be a faulty card

Hello guys, I am currently cleaning up a scada system that controls around 20 PLCs and I am having trouble with one PLC. its a ml1500, and i have an expansion card. Its something like a 1769 4 channel analog input card. Anyways, the card is sending me 32767 which wound indicate 20mA, but there is no current flowing. I checked the card config and it was set from 4-20 so i reconfigured it to 0-20, and its still sending me 32767. Any clue what might be causing this? Ill answer any other questions you guys need

as for zeroing out a floating point youre right, as stated above, a better idea is to subtract 1000 so you dont knock off the decimal. As for the timer issue, my applications have never been critical enough to where its become a problem, but you are 100% right. I think the infinite timer is the most straightforward approach

Subtracting actually does seem like a more accurate measure now that i think about it, that way you dont lose whatever few gallons passed through before the rung was executed

I use flow totalizers in a lot of the programs i write. Assuming you are getting flow in GPM, what i usually do is divide the input by 60 and move it into a new register, say F112:0. That new register represents Gallons per second. Then create a one second timer, we'll call it T4:0. When T4:0/DN is true (once a second) you add F112:0 to a register like F112:1, and put the result IN F112:1. that way it compiles your total flow every second. Then to get more depth, on the next rung, say if F112:1 > 1000 you add .001 to a new register like f112:2 and move IT into f112:2 to compile, and then you move a zero into F112:1, reseting it. this new F112:2 is your flow total in Millions of gallons. So essentially you add your gallons per second to a register every second, and every time it hits a thousand you add a .001 to a new register giving you your total in millions. Let me know if i need to explain it better