Last seen: Sep 19, 2026
It cannot see it. Your valve goes up and down in about 3 seconds and the historian takes one number every 30 seconds, so it gets one point per ten cyc...
Put a meter on the black wire with metal in front of the sensor. Solid 24VDC, out of the sensor's own supply. The F-DI pulls its sensor supply low for...
Copper is the problem, not the module. A thermocouple measures the difference between the hot junction and the point where its two metals stop and cop...
Changed it to 37001 and the 16#8383 went away, STATUS 0 and data came in on V16 first try. Floats are garbage though, numbers like 1.2e-40, and the to...
There is your zero. The 4-wire transmitter powered itself from its two supply wires and pushed 4 to 20 mA into the channel. The 2-wire one takes its p...
Meter 6 is the one with the terminator and the last on the chain. Check the jumper is actually across the bus pair and not a spare pair, and check A a...
No. The average is the wrong tool. Every sample in the window carries the same weight, so the newest one is 1% of the answer and a step takes the whol...
Loop's proved, good. Does the reading change with speed? A booster pump at two setpoints won't read the same. What do you get at normal speed and at f...
Loop first. At the valve, does the mA you measure match the Output the block shows, and is the valve signal to open or signal to close? If 20 mA is op...
It's not tuning, it's the two hours. Before the loop, prove the PV is honest: does the RTD read right when it comes back, no lag? Then the question: w...
You proved the sensor with the meter, so leave it alone. What's the common terminal for that input group wired to, +24VDC or 0V? That decides everythi...
Meter in series reads 0mA and 0V across the transmitter. So nothing is driving the loop. Before the PLC: what is powering the transmitter? A 2-wire un...
Right. Fit the resistor and measure again.
Photo attached. Three cores come in from the tank, two landed on the channel, the third cut back and taped. Its been like that since the job was hande...
The page heading says "Input Registers (3xxxx) read only" and then 7001, 7003, 7005 as float pairs. Photo of the page attached. The setpoints are in a...