Mitsubishi Electric NZ2GF12A4-16D User Manual page 132

When the L ER LED turns on
Check item
Are Ethernet cables normal?
Does the switching hub in the system normally operate?
Do other stations connected to the I/O module normally operate?
Is the mode of the module on the master station set to other than
Online?
Is there any noise affecting the system?
Is the loopback function enabled for the master station?
*1 When the I/O module is installed in the control panel or steel shelf, the FG metal fitting of the I/O module can be connected electrically
with them. Thus, if the control panel or steel shelf is not properly grounded, the noise may enter the FG through the control panel or steel
shelf.
When the LINK LED turns off
Check item
Are Ethernet cables normal?
Do the switching hub and other stations in the system normally
operate?
If link-up processing is repeated due to a condition of a device on the line, it may take a longer time for the
LINK LED to turn on.
This phenomenon may be eliminated by changing the module PORT into which the Ethernet cable is
connected (example: PORT1  PORT2).
11 TROUBLESHOOTING
130
11.3 Checking the LEDs
Action
• Check that 1000BASE-T-compliant Ethernet cables are used. ( User's manual
for the master/local module used)
• Check that the station-to-station distance is 100m or less.
• Check that the Ethernet cables are not disconnected.
• Check that a 1000BASE-T-compliant switching hub is used. ( User's manual for
the master/local module used)
• Check that the power supply of the switching hub is turned on.
Check that the power supplies of the other stations are turned on.
Change the mode of the module to Online.
• Check the status of wiring.
• Ground the control panel or the steel shelf where an I/O module is installed.
When the loopback function is enabled, check that the ring topology is correctly
configured for the PORT where the L ER LED is on. ( User's manual for the
master/local module used)
Action
• Check that 1000BASE-T-compliant Ethernet cables are used. ( User's manual
for the master/local module used)
• Check that the station-to-station distance is 100m or less.
• Check that the Ethernet cables are not disconnected.
• Check that a 1000BASE-T-compliant switching hub is used. ( User's manual for
the master/local module used)
• Check that the power supplies of the switching hub and other stations are turned on.
*1