1756-IF8 - PLC Programming & Automation

Setting Up a PID in Studio 5000: PIDE Gains, Units and the First Bump Test

The PIDE parameters that matter before tuning: PVEUMin and PVEUMax, CVEUMin and CVEUMax, DependIndepend, TimingMode, the three gains and the CV limits

Read process gain, dead time and time constant off one bump test, then enter them in the units PIDE actually wants instead of the ones the PID wants.

Reading a 4-20 mA Transmitter into a 1756-IF8: Wiring, Range and the Raw Value

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A 1756-IF8 analog input in integer mode lands on roughly -20,030 counts at 4 mA and 30,920 at 20 mA, which are not numbers anybody memorises. If the value in front of you is 3277, the card in the rack is a 1769-IF4 or 1769-IF8 running the Scaled-for-PID data format, and none of the 1756 … Read more

PLC Hardware Components and the Software That Uses Them

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Timing chart showing a field input rising, the input image bit following at the next input scan, the coil in logic changing during the program scan, and the physical output finally switching after the output scan, about one scan behind the field

What is in a PLC rack and how the software sees it: power supply budget, CPU memory, I/O cards, tasks and routines, and tags against S7 addresses.

PLC I/O Modules: Sinking, Sourcing, Keying, Scaling

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Timing chart of a 24V DC input: the field sensor edge, the module input filter delay, and the controller tag updating at the next RPI

How to pick discrete and analog I/O, get sinking and sourcing right, set RPI and electronic keying, wire a 4-20 mA loop and scale the raw counts.

PLC Water Treatment: Levels, Lead/Lag Pumps and Dosing

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Timing chart of lead and lag pump alternation: the lead call starts pump 1, the lag call brings in pump 2 at high level, and on the next cycle pump 2 takes the lead

Wet well level control, pump alternation that shares the wear, chlorine dosing with long dead time, and remote sites over cellular Modbus that go quiet.