Every PLC and HMI tutorial on plctr.com: project setup, ladder and structured text, communication, troubleshooting and commissioning, written from the plant floor.
Power up the cell and the 1734-AENT on Fa1/5 sits in module fault for about thirty seconds, every single time, then clears itself and runs all week without a hiccup. The adapter is fine, the drop cable is fine and the RPI is fine. That port spends its first 30 s after link-up walking through … Read more
Module Fault 16#0010: Mode or State of Module Does Not Allow the Object to Perform the Service The Connection tab of the module properties reads Module Fault 16#0010, and the sentence beside it says the mode or state of the module does not allow the object to perform the requested service. The general instructions reference … Read more
Unicast or Multicast on an EtherNet/IP I/O Connection: the Checkbox and What It Decides Module fault 16#0106 appeared on the second controller’s listen-only copy of a 1734-AENTR drop, and the string underneath it reads “Module owned and configured by another controller. Module may accept only one connection if Unicast is used.” The owning controller had … Read more
The Connection Timeout Multiplier on a 1756-EN2T: What It Buys and What It Hides A rack-optimised connection through a 1756-EN2T at a 100 ms RPI rides out 400 ms of total silence before the module goes yellow in the I/O tree. At a 10 ms RPI the same connection faults after 160 ms, not after … Read more
The CIP Generic MSG on a Logix Controller: Service Code, Class, Instance, Attribute Four boxes on the Configuration tab of the Message Configuration dialog, and the manual that tells you what to type in them is a different manual for every device you point the message at. Service Code 4B, Class 342, Instance 0, Attribute … Read more
Modbus TCP from a 1756-EN2T with the Socket Object: the Five Messages, the Frame, the Byte Order A 1756-EN2T in slot 3 at 192.168.1.10, a third-party power meter at 192.168.1.40 answering on port 502, and a MSG instruction that returns 16#00ff with an extended code of 16#0000_0046 on every attempt. Nothing on that network is … Read more
Line 2’s palletiser infeed stops about once a shift with Infeed_Jam latched, the alarm log says “Infeed jam” with a time, and the 1756-L83E, the PowerFlex 525 and the 1756-IB16 feeding the discharge photo-eye all check out every time somebody looks. Whatever happens takes a few tens of milliseconds and happens hours apart, and the … Read more
Inputs I0 and I1 on a 1791ES-IB8XOBV4 went solid red one afternoon with the guard closed, and the DCS instruction in the GuardLogix 5580 behind them has held Input Status false ever since. The guard switch on the infeed has two NC contacts in one four-core cable, the cable was crushed where it enters the … Read more
BadIdentityTokenRejected is the answer an OPC UA server gives when the secure channel is up, the client certificate is trusted, and the session request arrives with no user in it, and on an S7-1500 with guest authentication off that is exactly where a first Python OPC UA client stops. It is the third of four … Read more
K1 is a 110 V AC contactor on a saw, its coil is switched by a solid-state relay, the SSR is driven from output pair 0 of a 1791ES-IB8XOBV4, and every 600 ms the contactor makes a small tick you can hear from the door of the panel. The scope on O0+ shows why: the … Read more
A 1606-XLE240E Series B has a DC-OK relay on terminals 13 and 14 that closes while the 24 V bus is above 90 % of its set point, and a Raspberry Pi 4 needs 5.1 V and somewhere between five and twenty seconds of notice to halt without corrupting its card. Raspberry Pi panel power … Read more
The guard on the case packer closed at 14:07 and the infeed conveyor started on its own, with the blue reset button 4 m away and nobody within reach of it. The DCS instruction on that gate was configured Restart Type Manual, exactly as the drawing said, and the machine still restarted, because the button … Read more