3-3
Part Names and Functions Section 3-1
Parts, Installa-
tion, and Wiring
3-1-3 MS and NS Indicators
The indicators show the status of the Digital Controller and the DeviceNet
Network. 
Normal Indicator Display The MS and NS indicators are both lit green when the status of the Controller
and the Network are normal.
Indicator Name Color Status Meaning (main errors)
MS Module status Green The Controller is normal.
Red Fatal error
• Controller error
• Watchdog timer error (DeviceNet communications)
Non-fatal error
• Unit error
• Unit changed
• Display Unit error
• Non-volatile memory error
OFF No power is being supplied.
• DeviceNet communications power is not being sup-
plied.
• Power is not being supplied to the Controller.
• The Controller is being reset.
• Waiting for initialization to start.
NS Network status Green Online/communications established (normal network 
status)
Online/communications not established (waiting for 
connection to be established with the master)
Red Fatal communications error (The Controller has 
detected an error that does not allow communications 
with the network.)
• Node address duplication error
• Bus OFF error detected
Non-fatal communications error
• Communications timeout
OFF Offline or power supply is OFF
• Waiting for completion of the master’s node address 
duplication check.
• DeviceNet communications power is not being sup-
plied.
MS
MS
MS
MS
NS
NS
NS
NS
NS
Lit Flashing
Not lit