We are facing issues with 2 no. Of snap pac S 1 controllers out of which one controller status led is blinking 4 times in red color as per the blink codes provided in the snap pac manual it is written invalid Mac address .
One controller is showing 1 time orange blinking and for both the controller even after pressing the reset button seems to have no effect on the status led.
We are not able ping the ip also and also not able to download the program.
Can you tell the probable causes of such failure so that we can eliminate such failure for other controllers installed in site.
Is it necessary to connect the ground terminal of the controllers.