Intelligent Technologies (IT.) D77A I/O Module Products
MN05002001E For more information visit: www.EatonElectrical.com 3

Catalog Numbering System

Catalog numbers have three or five groups of characters, depending on the kind of module the catalog number represents. The
catalog numbering system used for IT. D77A I/O modules is illustrated as follows:
For discrete digital and analog I/O, the first four positions in the first group indicate the product family. The next two places in the
second group indicate the I/O type. The third group uses one or two places to indicate the number of points in the module. The last
group is used only for combination modules.
Table 2: Catalog Numbering System
Product Line Prefix
D77A = I/O Module Products
A = AC
D = DC
R = Relay
N = Analog
I/O Type
Number of Points
2 = 2 Points
Expansion Module
DQ8 (DC Output, 8 Points)
RQ8 (Relay Output, 8 Points)
AQ8 (AC Output, 8 Points)
AD77A
I = Input
4 = 4 Points
8 = 8 Points
16 = 16 Points
-
Input or Output
Q = Output
Q16 XX