Io Tunneling And Connection Safeguard - INSYS Modem 336 LL 2D/4D 5.x Originate / Answer Manual

Functions
12.7

IO Tunneling and Connection Safeguard

Every 20 seconds, or when the states of the digital inputs in the date stream change their
status, the INSYS Modem 336 LL 2D/4D 5.x Originate / Answer sends a test message to
the INSYS Modem 336 LL 2D/4D 5.x Originate / Answer of the remote terminal. This test
message is used to transmit the input states (IO tunneling) and to perform a function
check on the connection (connection safeguard). The maximum frequency for state
changes that are transmitted via IO tunneling is 0.5 Hz.
If the remote terminal responds to this test message within 120 seconds, the connection
is regarded as established and functional. If the test message is not responded to within
this timeframe in a regular manner, the INSYS Modem 336 LL 2D/4D 5.x Originate / An-
swer will re-attempt to establish the connection. For the test message, a certain ASCII
character is used. The ASCII character must be the same on each of the two devices of the
leased line. We recommend not using the test mark in the expected data traffic.
The default setting for the test mark for the connection safeguard is set to the ASCCI
character 3. IO tunneling and the connection safeguard are activated as default.
Configuration with AT commands
To completely switch the connection safe-
guard and the IO tunneling off, use the com-
mand
To define the ASCII character for the connec-
tion safeguard and the IO tunneling, use the
command
Set a number between 1 and 255 instead of
<y>.
38
INSYS Modem 336 LL 2D/4D 5.x Originate / Answer
ATS8=0
ATS8=<y>