15
CHAPTER 4: Configuration and Operation
Data Terminal Ready (DTR, Pin 20) and Clear to Send (CTS, Pin 5)
The signal fed into the Data Terminal Ready input (Pin 20) of a multiplexor
channel is transmitted to the other multiplexor, where it appears at the Clear
to Send output (Pin 5). The Clear to Send output is true whenever Data
Terminal Ready is true at the other multiplexor, even if Request To Send
(RTS, Pin 4) is false. (The multiplexor has no Request To Send input.) It is
possible that some terminal devices connected to the multiplexor may be
confused by this condition and not work properly.
Transmit Clock (TXC, Pin 15), Receive Clock (RXC, Pin 17), and Secondary
Transmit Data (STXD, Pin 14)
The received signal that appears as an output at Pin 17 (Receive Clock) of
one of the local multiplexor’s channels has two possible sources at the remote
mux:
If the corresponding channel of the remote multiplexor is configured for
internal-clock synchronous operation (Mode 4), that multiplexor’s Transmit
Clock output (Pin 15) also appears at the Receive Clock (Pin 17) output of
the local mux.
If the corresponding channel of the remote multiplexor has its channel-
configuration switch set with STD ON and all other positions OFF (Mode 2, 3,
or 5), any signal fed into the remote multiplexor on that channel on
Pin 14 (Secondary Transmit Data) appears on that channel at Pin 15
(Transmit Clock) and is transmitted to the local multiplexor, where it
appears at the Receive Clock (Pin 17) output.
