LC5 intermittent fast blink no contact error in MC43 system

Hello,

We are experiencing faults across multiple machines with LC5 levers.

The fault presents intermittently as a no contact error, and requires a power cycle to resolve.

The LC5 status light shows a fast blink pattern of 2 yellow, 15 red, then approx 30s of high frequency red blinks. See attached videos (split into 2 parts due to size restrictions). 

The MC43 in the system shows an R3:1 no contact error blink sequence. Please note that the LC5 is connected to our MC43 via an expansion bus connected with CAN-A. Our application cycle time is 20 ms.

The bus CAN-A contains 3 other devices. When the fault occurs, the other devices on CAN-A continue to transmit/receive CAN messages.

So far we have tried:

1. Checking canbus termination: 56 ohms

2. Increasing the polling cycle time from default to 80 ms. 

3. Checking CAN bus utilization. Busload after the of the fault was measured at

approx 36%.

We have also tried to replicate the fault by manually disconnecting power/can from the LC5, with no success.

Can anyone provide more information on the causes and possible solutions for this error?

lc5-fast-blink-SN-421040085-2of2.mp4
lc5-fast-blink-SN-421040085-1of2.mp4

Thanks in advance for any assistance.

Rhys Nicholls