Solving Memory Loss and Computer Lockup Problems

Controllers experiencing memory loss or lockup problems are typically being adversely affected by electrical noise. Controllers may also function erratically, reset intermittently, or may generate Error codes 0002, 0003, or 2200.

The following procedures will help alleviate these problems:

  • Check power supply(s) for proper levels. Clean, adequate DC power is required by AMS controllers.
  • Separate signal wires and DC wires from AC and high voltage wires. For example, encoder cables should not be run in a bundle with 440VAC and DC wires should not be mixed with AC wires in long runs of conduit. This can induce noise into the small voltage signals, the DC supply, and the controller inputs.
  • A good system chassis ground or earthing ground is necessary for proper operation. A grounding rod near the controller or console is sometimes necessary. Verify that the grounding system is adequate and meets all local and NEC requirements.
  • The power supply common should be connected to chassis ground at a single point. This connection should be made directly from the negative side (common) of the power supply to the system grounding rod or grounding block.
  • An isolation transformer should be used for the input of the control circuit and for the power supplies. The return wire (ACN) of the 110VAC from this transformer should be bonded to the ground rod (or block) at a single point making a separately derived power source. Be certain to follow all applicable local and NEC guidelines. The controller should be wired in such a way that it is powered up separately from the rest of the machine.
  • The controller should be properly grounded. This is best achieved by connecting a separate chassis ground wire from either the “SHLD” terminal on the controller or the mounting bolts of the controller directly to the ground rod or block.
  • Noise suppression devices should be on ALL output devices included on the machine. This will include relays, solenoids, clutches, electric valves and contactors on the machine. Rollformers, uncoilers, multiple presses, coolant sprayers and stacking devices should also be protected using the proper noise suppression devices. Mount these devices as close to the source of noise as possible.
  • Make sure that the machine wiring and power supplies are in good working order. Check for scraped wiring or faulty connections.
  • For Closed-Loop systems – Make sure that the drive is properly grounded. Most drives have terminals for this purpose.
  • For XL series controllers, the DC power to the controller should be supplied by two sets of twisted-pair wire. One set of twisted wires to A1 and A2 for the CPU power, and one set of twisted wires for the I/O power. These twisted wires should run directly from the power supply to the controller and should be routed away from all AC wiring or other noise-producing conductors.