Satel SATELLINE-1AS User Manual page 5

Operation description of the lines pin by pin:
1 DTR operates as an ON/OFF switch of the modem
2 CD indicates a signal on the radio channel exceeding the level of sensitivity of
the modem (it can record radio interferece signal).
3 and 4 Will be connected together in models with LEDs, where the most important
lines are indicated by leds.
5 RSSI measures the received signal strength of the field of the transmitting radio
(starts approximately from 0.5 V and goes up to 5 V ). The strength of the field
increases with the voltage. See appendix 4
6 CTS indicates when the radio data modem is clear to receive data via the
RS-interface
7 SGND is the signal ground
8 GND is the ground of supplying voltage
9 RD received data
11 TD input of transmitted data
13 RTS gives radio modem a request to send, starts the transmitter (answer by CTS
line)
15 Supply voltage
The RSSI (Received Signal Strength Indicator) is available on the radio data modem. This
feature indicates the level of field strength of an incoming transmission and is particularly
useful in systems that have several receivers as it is possible to select the receiving device
that has the optimum incoming signal.
The radio modem also incorporates a CD (Carrier Detect) line output which is activated
5...10 ms after the activation of the RTS line of the transmitting modem. The CD line also
indicates the presence of either a signal on the radio channel or an interference signal
above the sensitivity limit of the radio modem.
SATELLINE-1AS and SATELLINE-2AS
5
"0" (0 V...-12 V)
"1" (+5 V...+12V)