Mitsubishi Q PLC error 1401

[ARQ 0]

Hello MrPLC people. One of our PLCs stopped with the error 1401 It has been running for atleast 10 years. It is a Q06HCPU with 2 Intelligent function modules, one ethernet QJ71E71-100 and one profibus QJ71PB92D. There is 2 I/O modules, QX80 and QY80. Downloaded the error log from plc. 1415,CONTROL-BUS ERR.,2014- 4- 7, 1:22:17,,Slot No./Base No.(0);I/O No.(0),Nothing 1401,SP.UNIT DOWN ,2014- 4- 7, 1:56:15,,Slot No./Base No.(0);I/O No.(0),Nothing 1415,CONTROL-BUS ERR.,2014- 4- 7, 5:53: 8,,Slot No./Base No.(0);I/O No.(0),Nothing 1401,SP.UNIT DOWN ,2014- 4- 7, 5:58:10,,Slot No./Base No.(1);I/O No.(2),Nothing 1401,SP.UNIT DOWN ,2014- 4- 7, 6: 7:24,,Slot No./Base No.(0);I/O No.(0),Nothing Software is GX IEC Developer 7.04 and GX Configurator-DP 7.04. The diagnostics in GX IEC Developer shows that all the modules are red. I tried to redownload the program to the plc but same error. Tried the error reset function in GX IEC, Debug>System errors but didnt work. The ethernet cable and profibus cable is unplugged at the moment. both cables is used on our backup plc after crash. Is there a way to isolate the source of error or do i throw it in the trash can? Edited 20 May 2014 by ARQ

[Delbert 2]

Check for a number is registers SD5 thru SD15. the numbers is these registers will point to the slot number with faulty module. Other possibility could be a bad base unit.

[ARQ 0]

Hello and thank you for your response. I tried adding SD5 through SD15 in Online>Entry Data Monitor. Started monitoring but it did not show anything.

[Edwin 0]

I will suggest you remove all network cards(QJ71E71-100 & QJ71PB92D) and re-write the simple program without any network card setting and test. If the error able to reset means your network card or setting have something wrong.

[ARQ 0]

Thank you for your responce. I made a simple program, removed all modules except power supply and cpu. This made the diagnostics show error 1415 instead. I finally found a similar spare Base unit (Q38B-E) and plugged in all modules and downloaded the production program again, the errors disappeared! Have ordered a new Base unit (Q35B-E). Thanks all for helping me.