Driving a 24 V Solenoid from a 1769-OB16: Leakage Current and the Bleeder The 1769-OB16 specification table puts off-state leakage current at 1.0 mA maximum at 26.4V DC, and the footnote underneath tells you what to do about it: a 5.6 kΩ, 1/2 W loading resistor in parallel with your load. For a 24 V … Read more
The guard door opens once and gets recorded twice: 06:41:12.310 in the Logix log, 06:41:12.650 in the S7-1500’s diagnostics buffer. The two controllers are eight metres apart on the same machine, both nominally synchronised, and the gap is a third of a second every time you look. Neither clock is broken. The Logix side is … Read more
A 5069-L320ER comes out of the box with no IP address, both Ethernet ports DHCP-enabled and firmware revision 1.xxx on it. Set the address first and then flash it to 29.011 or later, and the controller quietly moves itself into Dual-IP mode, applies the address you just typed to port A2 instead, throws away the … Read more
The 1734-AENT drops out for roughly six hundred milliseconds once a shift, never twice in the same hour, and the controller log says the same thing every time: the connection timed out. That sentence tells you the connection stopped. It does not tell you which end stopped it, and while you do not know that, … Read more
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