compact logix not communicating with I/O

Hi,
i have a problem with my compact logix L35E controller.when i tried to download a program which was created in version 15.4,i updated the controller firmware to 15.4,but after downloading the program controller showing I/O communication error and processor going fault mode.can anybody help me.

Are you sure your I/O matches what you actually have? Modules snapped in properly? What fault are you getting?

Remember that CompactLogix controllers require an End Cap (1769-ECR) at the end of the I/O assembly, and that there are specific rules about how many modules you can connect before you need to use an expansion cable and another power supply.

You need to post details on the actual I/O modules and power supplies you are using, as well as details about the error codes you are seeing in the controller.

I am using 1769-L35E controller
slot
1 1769-SDN/B
2 1769-IQ16/A
3 1769-IQ16/A
4 1769-IQ16/A
5 1769-IQ16/A
6 1769-OB16/B
7 1769-IF8/A
8 1769-IF8/A
9 1769-IF8/A
10 1769-IF8/A
11 1769-OF8C/A

power supply(1769-PB4 series A) is in 3rd position from controller

when i am going run mode I/O status shows IO fault.(code 16#0010)mode or state of module does not allow oblect to perform requested service.

in controller properties window it is showing,"(Type 03) I/O fault,(code 23)at least one required connection not established before going in to run mode)

my 1769-SDN is in inhibit mode

Thank you for posting the followup information.

Those fault codes are consistent with a break in the 1769 I/O backplane connection or the absence of a 1769-ECR end cap.

Check each one of the 1769 bus connections to be sure that there are no bent pins and that the sliding bus connector is seated firmly and locked in place.

As I mentioned, CompactLogix requires the use of a 1769-ECR end cap attached to the rightmost module. The end cap contains termination electronics for the 1769 data bus.

Thanks.problem is solved.it was due to 1769-ECR

Thank you for posting the solution to the problem.