User Manual
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DIP Switch Settings 
IMC-21 Series (10/100BaseT(X) to 100BaseFX) 
DIP Switch 1 (Default OFF: FDX) 
FDX: Fiber port in full duplex mode 
HDX: Fiber port in half duplex mode 
DIP Switch 2 (Default OFF: LFP) 
LFP: Enables LFP (Link Fault Pass-Through) for 100BaseFX 
LFP DIS: Disables LFP for 100BaseFX 
DIP Switch 3 (Default OFF: FDX) 
FDX: TP port at full duplex mode 
HDX: TP port at half duplex mode   
DIP Switch 4 (Default OFF: 100) 
100: TP port at 100 Mbps 
10: TP port at 10 Mbps 
DIP Switch 5 (Default OFF: AUTO) 
AUTO: TP port in AUTO (auto-negotiation) mode 
FORCE: Force TP port into 10M or half duplex mode 
After changing the DIP switch setting, you will need to power off and then 
power on the IMC-21 to activate the new setting. 
LED Indicators 
The front panel of Moxa Industrial Media Converter contains several LED 
indicators. The function of each LED is described in the table below. 
IMC-21 series (10/100BaseT(x) to 100BaseFX) 
LED 
Color 
State 
Description 
P 
AMBER 
On 
Power is being supplied to the power input. 
Off 
Power is not being supplied to the power 
input. 
100M 
(FX) 
GREEN 
On 
FX port’s 100 Mbps link is active. 
Blinking 
Data is being transmitted at 100 Mbps. 
Off 
FX Port’s 100 Mbps link is inactive. 
FDX/COL 
(FX) 
GREEN 
On 
100BaseFX port is transmitting in full 
duplex mode. 
Blinking 
A data collision has occurred. 
Off 
100BaseFX port is transmitting in half 
duplex mode. 
100M 
(TP) 
GREEN 
On 
TP port’s 100 Mbps link is active. 
Blinking 
Data is being transmitted at 100 Mbps. 
Off 
TP port’s 100 Mbps link is inactive. 
10M 
(TP) 
GREEN 
On 
TP port’s 10 Mbps link is active. 
Blinking 
Data is being transmitted at 10 Mbps. 
Off 
TP port’s 10 Mbps link is inactive. 










