3Com CS/2500 Installation Manual

Contents

1-8 CHAPTER 1: O VERVIEWThe following sections describe these connectors. Pin assignments arelisted in Appendix A, “Pin Assignments. “Serial I/O Connectors The back panel provides ten serial I/O ports, labeled J0C through J9C,using horizontally mounted 25-pin D-series subminiature femaleconnectors (RS-232-D). All ten ports can be used to connect the serverto hosts, terminal devices, or modems. The communications server actsas a data communications equipment (DCE) device and can be attachedto a data terminal equipment (DTE) device, such as a terminal, host, orprinter, using a straight-through cable. If you want to connect the serverto a DCE device, such as a modem, use a null modem cable.You can also have one port serve as the console port. For moreinformation, see “Console Port” on page 1-8.The connector numbers on the back panel correspond to port numbersused by multiprotocol communications server software (connector J0Ccorresponds to port 0, connector J1C to port 1, and so on).RS-232 InterfaceThe default serial I/O interface for the CS/2500 series is RS-232-D. Forinformation about pin assignments, refer to Appendix A, “PinAssignments.”RS-422 InterfaceCS/2500 series serial ports also support RS-422 Transmit Data andReceive Data capabilities. Transmit Data lines are assigned to pins 13and 14 of the RS-232 serial connectors, while Receive Data lines areassigned to pins 16 and 19. Pin 25 is used for automatic detection ofRS-422 mode. For complete information on pin assignments, refer toAppendix A, “Pin Assignments.”Console PortYou can configure one of the ten serial I/O ports to serve as a consoleport. The default is port J0. An asynchronous terminal attached to theport can be used to:n Provide access to the server’s user interfacen Modify firmware configurationCS2500BookFile : Overview Page 8 Thursday, December 11, 1997 10:44 AM