carrier and DCD signal) with a hysteresis of 3 dB (detection of carrier
and DCD signal at R – 9 dB). The minimum reception level is –48
dBm.
Example:
AT&RL27 command line sets receive level at –27dBm. Modem
responds with “OK” message.
Serial Interface Mode
A T & S I x
Sets serial interface mode. Valid values for x are 0 to 6. In transparent
data mode with x=0, adjusting carrier control to DOX mode is invalid.
x = 0 Transparent data, no buffering
x = 1 Asynchronous data, with buffering
x = 2 Indactic Master, bit-synchronous data, no buffering
x = 3 Indactic Slave, bit-synchronous data, no buffering
x = 4 Indactic Master, asynchronous data, buffering
x = 5 Indactic Slave, asynchronous data, buffering
x = 6 ITU-R M.493-11 asynchonous data, buffering
Example:
AT&SI1 command line sets serial interface to asynchronous mode.
Modem responds with “OK” message.
RTS/CTS
Delay
A T & C T S x x x x
Sets delay between Request to Send (RTS) from the DTE and
confirmation by the modem in the form of Clear to Send (CTS). Valid
range is 40-6825ms.
Example:
AT&CTS50 command line sets RTS/CTS delay at 50ms. Modem
responds with “OK” message.
Fail If DCD Off
A T & D C D x
Turns on /off “Fail if DCD off” option. For x = 0 modem FAIL relay
doesn’t react on DCD changes. For x = 1 FAIL relay is switched on
when DCD = 0. CD led on the modem front side follows DCD
changes.
PTT When TX On
A T & P T T x
Turns on /off “PTT When TX On” option. For x = 0 modem PTT
relay doesn’t react on carrier On/Off changes. For x = 1 PTT relay is
switched On when carrier is On, and switched Off when carrier if Off.
This relay may be used to turn On external transmission equipment (for
example radio trasmitters).
Use SQ Input
A T & S Q x
Turns on /off “Use SQ Input” option. For x = 0 modem DCD (CD on
RS-232C and front panel LE diode) follows in-channel carrier presence
changes. For x = 1 modem DCD (CD on RS-232C and front panel LE
diode) follows SQ input state changes. SQ input may be used for
indication of in-channel carrier presence signalization when external
reception equipment is used (ex. radio receivers).
Use
DTR
A T & D T R x
Turns on /off “Use DTR” option. For x = 0 state of DTR input is
overriden and assumed that is always set to 1. For x = 1 DSR signal is
copied to DTR signal. Modem works properly only when DTR = 1.
IDM50B User Manual v1.2n, Rev. date: 24 februar, 2009
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