Every PLC and HMI tutorial on plctr.com: project setup, ladder and structured text, communication, troubleshooting and commissioning, written from the plant floor.
A GET on a CPU 1511 that reads from a CPU 1214C and comes back with ERROR = 1 and STATUS = 8 has almost always been refused by the 1214C, and the 1214C has no code in it to blame. Two settings on the partner decide whether PUT and GET ever return data, and … Read more
Siemens gives you a Retain checkbox and a published memory budget. Rockwell gives you neither. Here is what each one really keeps, and how to check it.
A 1769-IQ16 takes 8 ms to see an input. Here is the counter module that will not, the quadrature arithmetic, and where the pulses actually get lost.
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.
Pick between TON, TOF and RTO, find out what retentive actually covers on each platform, and stop losing an afternoon to a timer that never times out.
Store a ControlLogix project to a 1784-SD2 card, pick the Load Image setting you need, and what an upload or a card restore will not give back at 3am.
What a Studio 5000 alias tag shares with its base, how it changes a force and a cross reference, and the tag scheme an alias cannot fix on a 1756-IB16.
Find every instruction that writes a tag in Studio 5000, tell a write from a read, and work out why an output with two writers flickers on a 1756-OB16D.
Install a force on a 1756-L83E, enable it, then prove it is gone: the three FORCE indicator states, the GSV that reads force status, Remove vs Disable.
Count the safety functions before you pick the box. Where a 440R relay wins, where a 440C-CR30 takes over, and what a safety network adds to the job.
Pick a discrepancy time for a 1791ES dual-channel input from the device that drives it, know which setting the DCS instruction sees, and clear the fault.
Four lines of Python on a Raspberry Pi 4 read a CompactLogix tag – a REAL out of a 5069-L306ER – and nothing at either end is licensed. pycomm3 1.2.16 speaks EtherNet/IP to TCP port 44818 itself, which takes the OPC server, the Windows box it used to live on and the licence out of … Read more