So I've been assigned a project to replace some drives on a machine and seeing how it is a Sunday, I don't have anyone in person to ask this question to. So maybe PF could help! Due to some aging/failing motor drives, I'm trying to figure out if some replacement drives will be compatible with existing drives on the machine. This is where my question comes up, what constitutes if two drives are compatible? Do the drives somehow communicate with one another? I always assumed that the drives communicated with the system controllers and nothing else. Is this a wrong assumption?