Modem Overview
2-3
Table 2-1 LEDs
Label
Name
Description
OH
Off Hook
Lights when modem is off hook
CTS
Clear to Send
Lights when CTS signal is active
RTS
Ready to Send
Lights when RTS signal is active
RD
Receive Data
Flashes when modem is receiving data
from a remote modem
SD
Send Data
Flashes when modem is transmitting
data to a remote modem
CD
Carrier Detect
Lights when modem receives a valid data
signal (carrier) from a remote modem
TR
Terminal Ready
Lights when DTR signal is active
MR
Modem Ready
Lights when power on
