yellowbooks
Member
I am not a PLC beginner; I know nothing but I am writing about PLCs and am a bit confused about when to use the term module and when to use the term circuit card. It seems the term module is used most often but on some site, they never refer to modules only cards. Is there a subtle difference?
The way I have interpreted it and some assumptions I have made (PLEASE correct me):
1. The term module is most commonly used because it best describes a) the functionality, like processor or communication or input, and b) is a housing for a circuit card to be fitted into an expansion slot on a PLC chassis.
2. But, in some cases, a card could be slotted onto the chassis directly, 'raw' as it were. Perhaps in a situation where you need quickly to fit a redundancy card.
3. And, in some cases, one might have a module that holds multiple cards.
Thank you!
The way I have interpreted it and some assumptions I have made (PLEASE correct me):
1. The term module is most commonly used because it best describes a) the functionality, like processor or communication or input, and b) is a housing for a circuit card to be fitted into an expansion slot on a PLC chassis.
2. But, in some cases, a card could be slotted onto the chassis directly, 'raw' as it were. Perhaps in a situation where you need quickly to fit a redundancy card.
3. And, in some cases, one might have a module that holds multiple cards.
Thank you!
