Posted 11 Dec 2022 Hi all. I have a 1769-IT6 thermocouple/mv input module. It is connected to a micrologix 1500 unit. The green okay light illuminates on power up, but after you download the program and put it in run mode the processor faults. Terminal block with the cjc's are on the unit. The error message just says the I/O module has encountered an error. The hex code under status bit 6 is 179h. This error code is not in the manual. Has anyone else encountered this? Oh and I only have channel 0 enabled for type k thermocouple. Has anyone else had this issue, or know if it is a configuration issue. Any help would be appreciated. Thank you. Share this post Link to post Share on other sites
Posted 11 Dec 2022 Do you have an end cap on the right hand side of all your modules? Share this post Link to post Share on other sites
Posted 12 Dec 2022 Yes sir I do. It is just the MicroLogix 1500, then the 1769-IT6 module then the end cap. Share this post Link to post Share on other sites
Posted 12 Dec 2022 Undocumented error codes suggest hardware problems. Consider swapping in another IT6 to see if that's the case. Share this post Link to post Share on other sites
Posted 12 Dec 2022 Thanks pturmel. Thats what I was wondering. Just wanted to make sure I had everything configured and setup correctly. The setup seemed pretty straight forward. Share this post Link to post Share on other sites
Posted 12 Dec 2022 If this is not applicable, then ignore me. Is the 1769-IT6 compatible or does it have to be a 1762? I presume that you found the module when offline with the 1500. Share this post Link to post Share on other sites
Posted 12 Dec 2022 1762 is for ML100, 1200 and 1400 not the ML1500 that uses 1769 CompactLogix modules. Share this post Link to post Share on other sites
Posted 12 Dec 2022 Alan_505 would be correct. MicroLogix 1500 can use 1769 compactLogix modules. It reads and reconizes it when you do a read I/O. Thank you to everybody for your responses. Share this post Link to post Share on other sites
Posted 13 Dec 2022 I found a KB article (Access level: TechConnect) that *almost* talks about this:https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/19576/loc/en_US#__highlight It refers specifically to the -IF4 and -OF2 modules, but it may apply here too. In essence, there's a switch on the side of the module for bus or external power. If the module is set for external power and it and the base lose power at the same time, then the module will report that error to the PLC as it powers down, which causes the PLC to fault. It will still show that fault when it powers back up. That article refers to another one (Access Level: TechConnect):https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/17966 The second article refers to noise as the most likely cause, but starts out talking about 0xx79h but ends up talking about 0x300. Not sure what's going on with that... 1 person likes this Share this post Link to post Share on other sites
Posted 14 Dec 2022 Thank you. I will take a look at those. There is no bus/external power switch on the IT6. Thank you for the help. I will still take a look at the articles though. Share this post Link to post Share on other sites
