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What to Do If a Communications Failure Occurs

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If you are experiencing communications failure on a Turbo PMAC (meaning you cannot talk to the PMAC from the host computer), please try these suggestions before calling the Technical Support Hotline:


  • Make sure all necessary power and communications cables (e.g., Serial, USB, Ethernet) are properly inserted and secured.
  • Try cycling power (shut down the system and then power back up).
  • Make sure you have the latest version of PeWin32Pro2 or PeWin32Pro. You can download the newest versions on the Delta Tau Downloads Website: http://www.deltatau.com/DT_SoftwareDownload/SoftwareDownload.aspx
    Make sure you have the USB patch and the software compatibility patch if you are using Windows 7 / Vista.
  • Make sure you are using an account on your operating system (e.g. Windows) that has administrative privileges (see attached document for more details) and are running this program as an administrator.
  • If the red WatchDog LED is lit, check if there is a solid +5 V logic power supply to the board. If the rise time on the +5 V is too slow or the voltage fluctuates too much, WatchDog may trigger, disabling PMAC. Check the Hardware Reference Manual for your device to locate the +5 V logic and GND pins. You can check these with a DMM or an oscilloscope. If you have solid +5 V, try the following point.
  • Try using the reinitialization jumper to reset your card to factory default on powerup. Power down PMAC, put the jumper in place (Jumper E3 for UMAC Turbo CPU and Clipper, E51 for board-level PMACs, or depress the Reset Switch SW for Brick Series products while powering up) and power up. If this fixes your communication problem, then your PMAC's configuration caused the failure. In this case, while the jumper is still in place and the PMAC is powered up, issue a SAVE to store the factory defaults, power down, remove the reinitialization jumper, power back up, and then try reloading your configuration into the PMAC. From PeWin32Pro2, you can reload the configuration by clicking Backup->Restore Configuration. Issue SAVE and $$$ after reloading the configuration.
  • If your Real Time Interrupt (RTI) PLCs or Kinematics Subroutines are too long, they might also cause your PMAC to WatchDog. You can test if this is the case by just disabling the specific PLC (disable PLC0 or disable PLCC0) you might think is the culprit, or by disabling kinematics by setting Isx50=0 for the coordinate system in question. If after disabling these your PMAC does not WatchDog, you may have identified that they caused the problem and need to be shortened.
  • Make sure your PMAC and your host computer are connected to the same ground if you are using USB to prevent a ground loop from burning either your PC's USB hardware, your PMAC's USB communication hardware, or both.
  • If you lose TCP/IP communication, try plugging in the PMAC's USB cable. If the PMAC device shows up in the host computer's Device Manager, this is good news. You may be able to just store the IP address again using the "Configure Ethernet 100 BaseT" program (found from Start Menu->PMAC Executive Pro2 Suite->Delta Tau Common). Follow the following forum post to change the IP address: http://forums.deltatau.com/showthread.php?tid=730
  • You can also try connecting to the default Turbo PMAC IP address: If this works, your IP address just got reset, and you probably can just change it back to what it was using the aforementioned Configure Ethernet 100 BaseT program.
  • Try reloading the communications and bootstrap firmware according to the following forum post: http://forums.deltatau.com/showthread.php?tid=63&highlight=firmware. You will definitely need to do this if your PMAC USB device does not show up in the Device Manager when you plug it in, and it may need to be reloaded in other situations as well. If after reloading the firmware your USB device still does not show up, either the card is broken or your computer's USB hardware is broken.
  • If you are connecting to PMAC directly from an Ethernet adapter in the host computer, use a crossover cable. If you are connecting from a switch (hub, router), use a straight Ethernet cable.
  • When communicating via USB, if PMAC is powered down and powered back up while the host computer is still on, you probably must go to Setup->Force All Windows to Device Number from within PeWin32Pro2, and then Remove the PMAC USB device and reinsert the PMAC USB device. Its USB number has probably changed, causing PeWin to no longer recognize PMAC until you remove and reinsert the newly enumerated USB device.
  • It is possible for the Ethernet circuitry on PMAC to break separately from the USB circuitry. If this happens, you can actually switch to USB permanently if you do not want to send in for an RMA to repair the Ethernet circuitry.
  • Try connecting to PMAC with a different computer using the same PMAC communication settings. If this works, it may be possible that your host computer's USB, serial, or TCP/IP hardware is not functioning properly, rather than the PMAC's.
  • If using Serial communication, try cycling through all available baud rates within Setup->Force All Windows to Device Number->Properties... to see if any of them will connect when clicking "Test" on the Properties window. Make sure to use the following settings: Parity -- None, CTS Output (Enabled), RTS Control (Enabled).
  • If you are using Windows 7 and are having trouble communicating over the Serial port, try right-clicking your PeWin32Pro2 shortcut (whether it is on the desktop, or start menu, or wherever), and then select Properties-->Compatibility-->Compatibility mode, and then select "Run this program in compatibility mode for: Windows XP (Service Pack 3)."
  • If you are trying to insert a device in PeWin32Pro2 (by clicking Setup-->Force All Windows to Device Number-->Insert) but after clicking "OK", the device does not show up in the list, right-click your PeWin32Pro2 shortcut, go to the Compatibility tab, and make sure that the box marked "Run this program as an administrator" is checked.


If none of these suggestions fix your problem, please call the Technical Support Hotline at (818) 717-5656, 8 am-5 pm PST, to confirm that the product is broken and needs an RMA.

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