Rockwell Automation 1395 Discrete Adapter, Rev 3.XX-8.XX - Manual (Page 9)

Chapter 2
Hardware Description
2-3
Board Hardware Configuration
There are two board configuration options available for the Discrete
Adapter Board I/O, 120V AC or 24V DC. The 120V AC Adapter Board
configuration has a bank of four two watt resistors located directly above
J3. These resistors drop the 120V AC down, and it is then sent through a
rectifier and opto-isolator. The 24V DC version also has a bank of smaller
resistors. As this is the only difference between the boards, it provides an
easy method of identification.
ATTENTION: Verify the voltage rating of the Digital Input. If
115V AC is impressed across a digital input rated for 24V DC,
damage to the input circuit will occur.
Firmware Location
This board contains firmware version 3.xx. Figure 2.1 shows the physical
location of the chips.
Figure 2.1 illustrates the major hardware points on the board. The primary
function of the board is to provide scaling and transfer of feedback signals
coming from discrete I/O and being sent to the Main Control Board.