Switched Line Activation - Not Cdstl; Switched Line Activation - Cdstl - IBM 3708 Description

Switched Line Activation - Not CDSTL
1
3
DTR _ _
I
DSR 2
~4~
____________________________________ __
110...-_ . . . . .
1
1
3708 enables switched line.
2
3708 tests OSR. Normally OSR will not be present. However, if OSR is present, as in this example,
the 3708 waits up to three seconds for OSR to drop.
3
After checking to ensure OSR is not present, 3708 activates OTR and waits for incoming call to be
answered by modem and OSR to be presented. 3708 does not limit the time that it waits for OSR to
be presented.
4
OSR comes active. Connection is established.
Figure 2-11. Switched Line Activation - not CDSTL
Switched Line Activation - CDSTL
1
r
DTR
4
DSR
I
2
RI
-.J
1
3708 enables line. 3708 ensures the OSR is not already present and begins monitoring RI. There
is no time limit on Incoming call.
2
Incoming call Is received and modem presents RI.
3
3708 activates OTR and waits up to 20 seconds for OSR.
4
Modem presents OSR. Connection is established.
Figure 2-12. Switched Line Activation - CDSTL
2-22
IBM 3708 Description