Specifications
Documentation Number 232BSS4-0812m    1 
&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 – www.bb-elec.com 
B&B Electronics – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 – www.bb-europe.com 
Chapter 1 – Introduction 
The 232BSS4 provides communications to four devices from one serial 
port. Each port uses a dedicated UART and includes an 8K byte transmit 
buffer and an 8K byte receive buffer (16K bytes total). Each port can be 
independently configured for data rate, data format, and protocol. The 
Master port can send and receive data from one of the Slave ports while the 
other Slave ports continue to buffer data. The Master device can also 
broadcast the same message to two or more Slave ports at once. 
  The 232BSS4 can be configured to send data automatically to the 
Master port from each of the Slave ports when data is present with an 
optional preamble identifying the port. It can also provide two-way 
communications between the Master port and one Slave port at a time. 
Switching and control is done through user-defined three or four character 
command strings. All control sequences are removed from the data stream, 
making the switch transparent to the Slave devices. The PC setup software 
provided walks the user through all possible parameters. 
  Switches can be cascaded to expand the 232BSS4 to more than four 
ports. Two units can also be used back-to-back to provide automatic 
connection between devices over a single data channel. LEDs on the 
232BSS4 indicate when the unit is powered up and which port is selected to 
send data to the Master port. 










