Product Overview
Master
Port
DB9
female
Slave Port 1
DB9 female
Power the unit with 12 VDC.
(Use B+B SM16-12-V-P230-C1)
Master Port Pinouts
Cascading Port Combiners
methods of capturing the path to the master port, RTS and
automatic data sensing. The first slave port to either raise
its RTS line or transmit data captures the path to the master
port. The path will be locked on that slave port until it either
lowers its RTS line, or 60 milliseconds after the end of its
transmission. Note that the 232PTC does not buffer any data,
any data sent to the opposite slave port during this period will
be lost.
Handshake signals
The CTS signal on each slave port indicates to the slave
devices if the path to the master port is available. If the slave
port’s CTS line is high, data received by that port will be
transmitted out the master port. If CTS is low, the opposite
slave port has captured the path to the master and any data
at the inactive slave port will be lost. For example, if both
slave ports are inactive and have RTS low, CTS will be high
at both slave ports, indicating that the path is available. As
soon as one slave port captures the path by either beginning
its transmission or raising its RTS line, the CTS signal at
the opposite slave port will drop to the low state. The RTS
output on the pin 7 of the master port follows the RTS signal
level found on the active slave port.
Pinouts
All ports on the 232PTC are configured as RS-232 DCE
ports, using DB9 female connectors. Note that a null-modem
type connection will be required to connect the 232PTC9 to
other DCE configured ports. Tables 1 and 2 and Figure 2
show the configuration of each port.
Power
2.5 mm
phono
jack
232PTC9 Port Diagram
Data flow from master port to slave ports
All data that is sent to the TX line, pin 3 on the master port,
is broadcast to both slave ports under all conditions. This
data appears on pin 2 of each slave port.
Data flow from slave ports to master port.
Data that is sent to the TX line (pin 3) on the slave ports
must compete for the path to the master port. There are
two
Slave Port Pinouts
Port combiners can be cascaded by
connecting the master port of each successive
unit to one of the slave ports of the preceding
unit. Each additional port combiner adds one
slave port to the system.
Slave Port 2
DB9 female
3
2
7
8
5
TD
RD
RTS
CTS
TD
RD
RTS
CTS
3
2
7
8
5-
RD TD RTS
2 3 7
CONTROL
CIRCUITRY
GROUND
PORT 1
PORT 2
MASTER
PORT
5
SIGNAL
PIN
DIRECTION
TD
3
Input
RD
2
Output
RTS
7
Output
GND
5
*****
SIGNAL
PIN
DIRECTION
TD
3
Input
RD
2
Output
RTS
7
Input
CTS
8
Output
GND
5
*****
Power the Unit
1
Connect Serial Cables
2
Operation
3
+
