Siemens Simatic S7-400 - Manual (Page 485)

M7-400 Expansions
12-15
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
12.3 ATM 478 AT Adapter Module; (6ES7 478-2CA00-0AC0)
Characteristics
The ATM 478 AT adapter module is used to accommodate a short AT module
(card).
The ATM 478 AT adapter module has a 120-pin connector on the left-hand side
and a 120-pin socket on the right-hand side for connecting a further expansion
module or a mass storage module.
Figure 12-7 ATM 478 AT Adapter Module