A Node-RED Logix tag read takes one install script, one palette install and two dialogs on a Raspberry Pi 4: Zone7_Speed from a 5069-L306ER appears in the debug sidebar as 30.0, and none of it involves typing a line of code. The node that does it is node-red-contrib-cip-ethernet-ip 1.1.3, installed from the palette manager, configured … Read more
A 1734-AENT on a remote I/O rack stores its chassis size in non-volatile memory, and the user manual says in as many words that the chassis size setting is not communicated to the adapter during a connection request from the controller. Download a project with the new rack in it and the adapter you just … Read more
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
16#0204 appears twice in the same Rockwell reference manual with two different meanings, and which of the MSG instruction error codes tables you are reading decides where you spend the next hour. In the extended error codes for error 0001 it is Unconnected message timeout. In the module fault codes it is Connection Request Error: … Read more
Assembly instances, sizes, Comm Format and RPI for a device with no catalogue profile and no EDS file, plus the connection error codes that follow.
A 300 mm tote leaving zone 12 at 0.280 m/s onto a metering belt running 0.513 m/s arrives at the scanner 250 mm behind the tote that left in front of it, and a 600 mm carton on the same two belts arrives 499 mm behind its neighbour. Neither number has a timer in it: … Read more
The infeed conveyor’s GuardLogix 5580 consumes one safety tag from the case packer’s 5580, CP_Safe, and at 02:04 every night for a week CP_Safe.ConnStatus.ConnectionFaulted went to 1 for between two and nine seconds, the consumed data went to zero, the conveyor’s CROUT dropped its contactors, and the shift lead reset it and wrote “network” on … Read more
The E-stop is reset, the safety relay is closed, every one of the twelve PowerFlex 525s on the accumulation line has S1 and S2 at 24 V again and F059 cleared from its display, and nothing moves. No fault on any drive, no alarm on the HMI, twelve zones with a carton on every eye … Read more
Two PowerFlex 525s with 42.50 Hz on both keypads were running the takeaway at 0.500 m/s and the palletiser infeed it hands over to at 0.462 m/s, and every carton that crossed the transfer between them arrived 7.6% closer to the one in front than it had left. A 1219 mm carton that left the … Read more
Bit 0 of the PowerFlex 525 logic command word is Normal Stop, and it has to be sitting at 0 before bit 1 will ever start the drive. That footnote under the table in Appendix D of 520COM-UM001 is behind most of the drives that show a green connection in the I/O tree and still … Read more
Wireless PLC communication done properly: choosing Wi-Fi, 900 MHz radios or cellular, RPI and timeout budgets, antennas, roaming, and link loss logic.
Write an AHU sequence on a CompactLogix: damper minimum position, supply fan VFD, chilled water PID, economizer changeover, compressor staging and BACnet.