\ \(em\ Data station A is in the normal operating condition. The loop is
established by a switch on DCE B.
.LP
\fINote\ 2\fR
\ \(em\ In DCE A, the condition of circuit 107 will be determined by the
condition of circuit 108. When circuit 108 is not provided on the interface,
circuit 107 is ON. The normal case is considered in the table.
.LP
\fINote\ 3\fR
\ \(em\ When loop 4 is in a unit separate from the DCE, the signals to DTE\ B are desirable but not mandatory due to the difficulty of implementation. When the loop is implemented within the DCE, loop establishment shall always be
possible by a switch on the DCE.
.LP
\fINote\ 4\fR
\ \(em\ The conditions represented by ON in the table may also activate a
visual indicator on the DCE.
.nr PS 9
.RT
.ad r
\fBTable 1/V.54 [T1.54], p.\fR
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
.sp 1P
.LP
4.2
\fIAutomatic control through the DTE/DCE interface\fR \|(see Table
2/V.54)
.sp 9p
.RT
.PP
Automatic control through the interface is achieved by using
circuit\ 140, 141 and\ 142 as defined in Recommendation\ V.24. Circuit\
140 is used to control loop\ 2 and circuit\ 141 is used to control loop\
3. The turning ON of circuit\ 142 indicates the
test mode
is established. If circuit\ 107 is ON, the associated terminal is concerned
and subsequent data transmitted on
circuit\ 103 will be looped back on circuit\ 104. If circuit\ 107 is OFF, the
associated terminal is not concerned.
.PP
\fINote\ 1\fR \ \(em\ Automatic control of loop\ 4 is considered of no
use either locally or in the remote station and therefore is not provided.
.PP
\fINote\ 2\fR \ \(em\ As an alternative to activation of loop\ 3 via circuit\
141, it could be activated via the four\(hyphase procedure defined in \(sc\
4.2 here.
.bp
.RT
.ce
\fBH.T. [T2.54]\fR
.ce
TABLE\ 2/V.54
.ce
\fBInterface signalling for automatic control of loops\fR
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(24p) | cw(24p) sw(24p) | cw(30p) sw(24p) | cw(30p) sw(24p) | cw(48p) , ^ | c | c | c | c | c | c | ^ .
Loop Control signals from DTE A Signals to DTE A Signals to DTE B Notes