ProSoft Technology 3170-MBS User Manual
Page 30

Diagnostics and Troubleshooting
3170-MBS ♦ Flex Platform
User Manual
Modbus Slave Interface Module
Page 30 of 55
ProSoft Technology, Inc.
October 27, 2010
6.1
LED Indicators
The following explains the operation of the LEDs.
LED
Color
Status
Indication
Power
Green
On
Normal state: The module is operating normally, with
communications being detected on the link
Blink
Modbus Communication Timeout: The port has not detected any
communications on the link for over 1 second. If the HOLD LAST
STATE dip switch is not set, the Input and Output images will be
forced to zero(0).
FLEX Backplane Communications Fail: The communication
adapter either does not detect any I/O modules plugged into the
backplane, or the backplane communications have failed.
Transmit Green
Blink
The Modbus port is transmitting data.
Receive Green
Blink
The Modbus port is receiving data. LED flashes on any character
activity, valid or invalid.
COM
ERR
Amber
Off
Normal State: When the error LED is off and the related port is
actively transferring data, there are no communication errors
Blink
Periodic communication errors are occurring during data
communications. Error conditions that cause LED to blink include:
Bad Function Code
Invalid Register Address in command
Invalid Count value in command
Insufficient Characters in Modbus Packet
Checksum Error detected in packet
FLEX Backplane Communications Fail: The communication
adapter either does not detect any I/O modules plugged into the
backplane, or the backplane communications have failed
On
This LED will stay on under several conditions:
Configuration Error
Recurring communication error