Installation manual
Publication 1394-IN002B-EN-P — February 2004
1394 SERCOS Interface Connector Data  2-15
Understanding I/O 
Specifications
A description of the 1394 discrete inputs, analog outputs, relay 
outputs, SERCOS connections, and logic power connections is 
provided on the following pages.
Discrete Input Specifications
Two fast registration inputs and four other inputs are available for the 
machine interface on the four discrete input connectors. These are 
sinking inputs that require a sourcing device.
IMPORTANT
To improve registration input EMC performance, 
refer to the System Design for Control of Electrical 
Noise Reference Manual (GMC-RM001x-EN-P).
IMPORTANT
The discrete input 24V dc power supply is 
user-supplied.
IMPORTANT
Overtravel limit input devices must be normally 
closed and configured in RSLogix 5000.
Discrete Input Pin: Signal: Description:
Capture 
Time
Edge/Level 
Sensitive
Axis 0-3 input pin 1 ENABLE A 24V dc input is applied to these terminals to enable each axis. 50 ms Level
Axis 0-3 input pin 2 HOME
The Home switch input is a normally open or normally closed contact 
configured in RSLogix 5000. Inputs for each axis require 24V dc (nominal), 
15 mA (max) to energize. Each input is optically isolated and filtered to 
minimize switch bounce. Refer to Figure 2.9.
50 ms Level
Axis 0-3 input pin 5 
Axis 0-3 input pin 6
POS_OTRAV 
NEG_OTRAV
The positive/negative limit switch input is a normally closed contact 
configured in RSLogix 5000. Inputs for each axis require 24V dc (nominal), 
15 mA (max) to energize. Each input is optically isolated and filtered to 
minimize switch bounce. Refer to Figure 2.9.
50 ms Level
Axis 0-3 input pin 7 I/O_Com Common grounding point for input signals (Home, Enable, Pos/Neg_Otrav) N/A N/A
Axis 0-3 input pin 3
Axis 0-3 input pin 4
Axis 0-3 input pin 8
REG_COM 
REG_1 
REG_2
24V dc high-speed, optically-isolated filtered registration input for each 
axis. Refer to Figure 2.10.
500 ns Edge










