Rockwell Automation 1771-DA,D17716.5.13 U MNL 1771-DA ASCII I/O MODULE - Manual (Page 34)

Getting Started with Your ASCII Module
Chapter 2
2Ć27
the rack, group, and slot number of the module address in the block
transfer read and write instructions, accordingly.)
3. Turn on power to the I/O chassis. Three LED indicators on the
ASCII module illuminate momentarily. Their functions are:
FAULT: Normally off. This red LED indicator illuminates when the
module detects an internal fault.
BUFFER FULL: Normally off. This yellow LED indicator illuminates
when the input buffer becomes full.
CHANNEL ACTIVE: This green LED indicator illuminates when the
industrial terminal is on, properly connected to the ASCII module’s
interface port, and set for alphanumeric mode.