Telenetics RM16M - Versatile Rack Mounting Chassis, Installation And Operation Manual, Page: 42 / 49

Digital Interface Descriptions
Page 42
Table C-2. Digital Interface Signal Descriptions (232D)
Pin
No. EIA-
232D
CCITT Signal Name Description
15 114 Transmit
Clock (DCE) A transmit data clock output for use by an
external data source. Positive clock
transitions correspond to data transitions
16 Not used
17 DD 115 Receive Clock A receive data rate clock output for use by
the external data sink. Positive clock
transitions correspond to data transition.
18 141 Local
Loopback
(Loop 3)
Control A positive level will cause the modem to
go into a local analog loop, when strap
enabled.
20 CD 108.2 Data Terminal
Ready This circuit is positive when the DTE is
ready to originate or answer a call in dial
up operation. DTR must always be active
(high) in 2-wire private line operation.
Cycling DTR causes retraining.
21 140 Remote Digital
Loopback A positive level will cause a digital
loopback at a remote modem, when strap
enabled.
22 CE 125 Ring Indicator In a direct dial operation, this circuit is
positive in response to an incoming ring
signal.
23 CH 111 Data Rate
Select Supplies a data rate control to select
Primary or Fallback data rate.
24 DA 113 External
Transmit
Clock A serial data rate clock input from the
data source. Positive clock transitions
correspond to data transitions
25 142 Test Mode Indicates when the modem is in a test
mode.