User guide

SATELLINE-3AS NMS / NMS Epic / NMS 869 / VHF
User Guide, Version 1.0
35
2) D
Data on channel
CD will switch to active state only after recognizing a valid data transmission from another
SATELLINE-3AS NMS family radio modem. CD will not react to interferences like noise or
possible other signals.
3) A
Always ON
CD is always in the active state. This option is usually used with terminal equipment using the
CD line as an indicator of an active connection. In this case the radio modem can transmit and
receive data at any time.
5.6.3
RTS line
RTS (Ready To Send) is a signal from the DTE to the radio modem. DTE controls the data flow
from the radio modem by using RTS. The options for RTS line controls are:
1) I
Ignored
RTS line status is ignored.
2) F
Flow control
The radio modem transmits data to the terminal device only when the RTS line is active. Inactive
state of the RTS line will force the radio modem to buffer the received data. This option is used,
when the terminal device is too slow to handle data received from the radio modem.
3) R
Reception control
RTS line controls the reception process of the radio modem. An active RTS line enables
reception. Inactive RTS line will interrupt reception process immediately, even if the radio
modem is in the middle of receiving a data packet. This option is used to force the radio
modem into WAIT State for an immediate channel change.
5.6.4
DTR line
DTR (Data Terminal Ready) is a signal from the DTE to the radio modem. DTR has a special
function in the radio modem - it can be used as an external ON/OFF switch for power saving
purposes.
The radio modem is:
• ON, if the voltage at the DTR pin is more than +2 VDC.
• OFF, in the Stand-by Mode if the voltage at the DTR pin is less than +0.6 VDC.
Note: If the DTR pin is not connected, the radio modem is ON.
!