Rockwell PLC Software: Which Tool for Which Controller
A working map of Rockwell PLC software: Studio 5000 editions, RSLogix 500, RSLinx Classic against FactoryTalk Linx, View ME and SE, Emulate and firmware.
ControlLogix
Paper Machine Draw Control, Consistency and Winder Tension
Sectional drive draws on a paper machine, the ratio calculation in ST, consistency and basis weight loops, and winder taper tension that holds.
Redundant PLC Systems: ControlLogix Pairs and S7-1500R/H
What a 1756-RM2 pair buys you, the design restrictions nobody mentions until commissioning, real switchover times, and when redundancy is the wrong answer.
Generator Start Permissives, Sync Handover and Load Shed
Where the PLC stops and the relay starts, a generator start permissive rung, the synchronising handshake, load shed stages and switchgear interlocks.
SCADA PLC Integration: Connect Ignition to ControlLogix
Pick the protocol, prepare the controller tags, add the device in Ignition, set a sane tag group, then prove the link survives a network drop.
PLC Scan Time and Cycle Time: Measure It, Then Cut It
Read real scan times with GSV on a ControlLogix and the cycle time view on an S7-1500, then find what is eating them before the watchdog does.
PLC PID Control: Set Up and Tune a Loop in Studio 5000
Scale the analog signals, pick PID or PIDE, put the loop in a periodic task, then tune from a bump test. Siemens PID_Compact covered as well.
ControlLogix Ladder Troubleshooting, Rung by Rung
A rung by rung ControlLogix ladder troubleshooting method: read the highlighting, use cross reference and search, find double coils, read the fault record.
Allen-Bradley Faults and Solutions: Read the Type and Code
The controller is in Program mode, the OK indicator is flashing red, and the Major Faults tab in Studio 5000 reads Type 4, Code 20. Two numbers, and they are the whole diagnosis. An instruction reached for an array element that does not exist. Nothing is wrong with the hardware. Type tells you which part … Read more
Allen-Bradley Function Block: What Decides Execution Order
A function block routine that verified fine last week now has a question mark on four blocks and will not download. Or worse, it downloads, runs, and one value on the HMI is always one scan behind the others. Nobody moved a block. Somebody added a wire. Execution order in FBD has nothing to do … Read more
PLC Sequencer Instructions: SQO, SQI and the Position 0 Trap
An eight-station rotary indexer on a 5069-L330ER. An SQO drives the station outputs, and on the first false-to-true transition the outputs light station one. Not station zero. Station zero never fires at all, and the operator wants to know why the first pot off the carousel is empty. That is not a bug in your … Read more
PLC Controller Firmware Upgrade
When you buy the plc CPU for the first time, you need to upgrade to the appropriate version for your program. If your program is written with version 30, you need to upgrade your CPU to version 30. CPUs come as version 1 by default. You can easily upgrade the CPUs of PLCs with Firmware … Read more
Advertisement