Hi all,

I have a simple question. We have two digital input cards. Which have same order codes in front cover of them. It is 321-1BL00-0AA0 andtheyare remote I/O modules.

However one of them has a sign in front cover like in coordinate system and it writes X-6-7-8 and the other one has X-7-8-9 (clockwise). What is the difference between them?

OK dear expert.

Thank you so much for your answer.

another last question.

There are some differences between remote I/O's as hardware addressing. Some of them has backside mechanical differences to prevent wrong placing in installition. also front mechanical differences to prevent wrong connection of connectors.How can I understand which one is correct one by looking their codes?