An optimized block on an S7-1500, or on an S7-1200 at V4.x, is created with a 100 byte memory reserve, which is room for 25 Reals of new Statics before a download in RUN has to reinitialise the instance DB. Whether an S7-1500 interface change makes the load preview put “reinitialize” against the block is … Read more
A UDT holding a STRING, eight REALs, four DINTs and four BOOLs is 140 bytes, and the Data Type Editor in Studio 5000 prints that number under Data Type Size before you have written a rung. Fifty of them in a PLC recipe UDT array is 7000 bytes and one base tag, and that last … Read more
Produced and consumed tags stop at 500 bytes, and at 480 once the data crosses a network, because the transfer spends 20 of them on overhead. Try to produce an INT array and Logix Designer refuses: DINT, UDINT, LINT, ULINT, REAL and LREAL are the atomic types that go across on their own, and anything … Read more
A CPU 1516-3 PN/DP in RUN on the filler, a SIMATIC memory card behind its front flap, and no project file on any laptop in the building. An S7-1500 upload – online, Upload device as new station (hardware and software) – and about three minutes later an empty project holds the rack, every block with … Read more
An S7-1500 area length error leaves the CPU in RUN with the ERROR LED on. Read the buffer entry, find the index that runs past the array, fix the order.
Add one Static to an FB and every setpoint in the instance DB goes to zero. How the memory reserve prevents it, how to size it, and how to recover.
What a warper, a sizing line and a stenter need from a PLC: draw ratios, dancer and load cell loops, yarn break stops and recipes on S7-1500 or Logix.
Injection molding from the controls side: the cycle as a state machine, barrel zone PID and thermocouple checks, EUROMAP 67 and 77, guards, and rubber.
Build PLC predictive maintenance on hardware you own: vibration and motor current inputs, runtime hours, moving averages, baselines and alarm levels.
How the BPCS, the SIS and the package PLC split the work on a batch reactor, with a cause and effect matrix, cascade temperature control and IS barriers.
PLC vs DCS programming compared by an engineer who works on both: tags and rungs against loops and blocks, redundancy, alarms, batch and real cost.
Build PLC batch control the ISA-88 way: procedure and phase breakdown, the phase state model, recipe parameters in a UDT, hold and restart logic.