Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 42)

Installation
Chapter 3
3-18
There are 6 LED indicators on the front of a KF2 module (Figure 3.10).
These indicators can help you in diagnosing problems with the module’s
installation and operation. The indicators are:
PWR - Power On
XMTG - Transmitting
RCVG - Receiving
RDY - Ready to Transmit
ACTV - Active
CPU - Module Fault, or DLE NAK Indicator
Figure 3.10
Diagnostic (LED) Indicators
XMTG RCVG RDY ACTV CPU PWR
ALLEN–BRADLEY
DATA HIGHWAY
COMMUNICATION INTERFACE
The XMTG light comes on when the KF2 module is current master of the
network link and is transmitting a command or reply message.
The RCVG light comes on when the module is receiving a command or
reply message from another station on the network link.
If the KF2 is on the Data Highway and the XMTG and RCVG lights are
on at the same time, this indicates that the module is current master of the
Data Highway and is polling the other stations to transfer mastership.
If the KF2 is on a PCL link and the XMTG and RCVG lights are on at the
same time, this means that the module is determining whether there is a
new module trying to access the link. This is known as “soliciting a
successor.”
The RDY light comes on when the module has a message stored in its
transmit buffer and it is waiting to acquire mastership of the network link
so it can transmit the message.
Diagnostic Indicators