LDC1430 "crashes" and stops responding. Requires power cycle to resume operation.

I have four LDC1430 units hooked up to four gearmotors running in open loop mode. The units are controlled over serial using an 8-port USB to Serial hub.

The issue is as follows:

-Sometimes, a controller will cut out (stop functioning). So far, two out of the four controller have done this at least once.

- Looking at the LEDs on the controller, they continue to blink normally, indicating serial mode. Looking at the serial hub, the TX light keeps flashing indicating data is being sent, however the RX light stops flashing, indicating that the device is no longer responding to the commands.

-Opening the serial port manually using a program like minicom confirms that the device is non-responsive.

-When the controller cuts out, the motor is no longer driven (ie: it does not latch at some value, output goes to 0)

-Power cycling the controller by removing, and restoring electrical power immediately restores functionality. Aside from power cycling, the unit will not resume functioning on its own, even if left alone for a long time (say, 15 minutes).

When the problem occurs:

-The problem usually is triggered when the motor being driven is stalled or put under high load.

-The controller is rated at 120A and I was testing the whole system using a 30A lab power supply for all four controllers, so overloading is definitely not the issue.

-Perhaps the issue could be browning out/low voltage due to the extra load and low amperage supply. However, other controllers and an onboard ATX PC keeps functioning normally. These devices are all running off the same supply. Additionally, I have not drawn the full 30A available. so I suspect this is not the case.

-Perhaps there is some sort of "feature" currently enabled that I am not aware of that is causing this?

Troubleshooting advice would be appreciated.

Are you running any type of script?

As for the loss in connection, is the motor running smoothly when this happens, or is the motor turning violently in both directions?

What is the firmware date of those controllers?

Does the Run tab throw any type of status errors, such as overheat, short, Mosfail?

-I am using the controllers directly as out of box and connecting via serial, so no scripts.

-The motor is running smoothly, then stops all together.

-The firmware date is an oddity. on two of the controllers (the ones that hadn't crashed) it was listed as 10/10/13 (if I recall correctly). The two which had crashed at least once showed the same firmware version, but the date was the current date (IE: on the day of testing it read 3/14/14).

-I am not sure what you are referring to in regards to "run tab". I am using the motor controllers in Ubuntu linux using a custom coded C++ program. For direct communication and testing, I have been using the serial terminal software, Minicom. However, as I mentioned, once this situation occurs I am unable to continue communication so I can not poll the device for any status messages using minicom.

I suggest you flash the firmware using the Roborun+ utility to the 10/10/13 firmware.

dev.roboteq.com/dev1/index.php/support/downloads