Chapter 2. Multiplexer to Challenge, Onyx, and Origin
Installation and Cabling

This chapter covers the physical placement and cabling of the multiplexer and other hardware components necessary to administer a Challenge, Onyx, or Origin site. Some basic troubleshooting information is provided.

The following topics are covered:

Installation and Cabling Summary

It is important that all installation and cabling steps be followed in order, or the IRISconsole system administration procedures may not work properly. The procedures are as follows:

  1. Load all applicable multiplexer and IRISconsole software and operating system upgrades onto the workstation using the CD(s) provided with the IRISconsole option.

  2. Shut down and power off the workstation.

  3. Select the SCSI device ID for the multiplexer and install all cables.

  4. Power on the multiplexer and then the workstation.

  5. As superuser (root), enter /sbin/cdmknods to create tty devices corresponding to the SCSI device ID used by the multiplexer.

  6. Start the IRISconsole window system and begin adding sites.

Loading Software on the Workstation

To make the IRISconsole system work, you must load the required IRISconsole applications onto the workstation. Note that the IRISconsole software and drivers can be ordered separately.

Follow these steps:

  1. Load the IRISconsole CD into a drive.

  2. As superuser, bring up the software manager by entering swmgr at the prompt.

  3. After the interface comes up, load the appropriate applications (for example, IRISconsole for 6.2 if your workstation is running IRIX 6.2) from the disc into your IRISconsole workstation. Note that if you have reference (man) pages or online help remotely mounted, the swmgr interface returns an error message. Select and load only the core applications to prevent this error.

  4. Reboot the workstation after loading all the applications.

  5. If you are bringing up the workstation for the first time after multiplexer installation, or have changed the multiplexer SCSI device ID, then you must enter /sbin/cdmknods as the superuser. This creates tty devices corresponding to the SCSI device ID used by the multiplexer.

  6. Bring up the IRISconsole interface by entering /usr/sbin/ic at the shell prompt.

  7. Select the appropriate interface(s). See the IRISconsole Administrator's Guide (P/N 007-2872-nnn) for information on the IRISconsole GUI.

Cable Connections

As mentioned in Chapter 1, the multiplexer site administration station should be physically connected (cabled) to each system you want to monitor. Silicon Graphics sells 25-foot (7.62 meter) serial cables (see Table 2-1) with 25-pin serial connectors at one end and 9-pin connectors at the other end.

These cables are designed for connecting the multiplexer specifically to deskside and rackmount Challenge and Onyx systems.Cables for connecting the multiplexer to desktop Challenge S systems
(P/N 018-0526-001, marketing code XDIC25) can also be ordered separately.

See your sales or service representative to find out about additional cables available for your multiplexer. Chapter 3 has information on pin and signal specifications for customers who wish to assemble their own cables.

Caution: To remain in compliance with all regulatory emission limits, use properly shielded and grounded cables and connectors.

Cabling and SCSI Guidelines

Each multiplexer is capable of connecting to a maximum of eight systems at a site. To cable the maximum number of systems, follow these guidelines:

  • Daisy-chain multiple multiplexers together using short SCSI cables that do not exceed a total of two meters (6.6 feet). Note that you should count an additional 6 inches (2.4 cm) of length for each device on the SCSI bus.

  • Select a different SCSI ID number for each multiplexer. Never select SCSI ID 1 or 0 for any of the multiplexers.

  • Use Silicon Graphics serial cables that match the pinout listings shown in Chapter 3.

  • Always properly terminate the last SCSI device on a chain.

  • When a serial cable is connected from the multiplexer to port tty_1 on Challenge or Onyx systems, do not use the 8-pin powered serial connector below it. Silicon Graphics recommends the use of RS-232 serial cables no longer than 50 feet (15.2 meters). Longer runs introduce a greater possibility of line noise occurring. This can affect data transmission and cause errors. For cable runs longer than 50 feet (15.2 meters), use an appropriate extender device.

  • To make the cable connections consistent and easier to organize, you should connect port 1 on the multiplexer to serial port tty_1 on all systems, with the exception of the Origin2000 and Onyx2 rack configurations (see “Connecting the Multiplexer to Challenge, Onyx, and Origin Systems”). Port 2 on the multiplexer is then connected to a specified port on the system. Repeat the process for all the multiplexer connections. Follow the same guidelines if you add a second multiplexer to the workstation.

  • Place a label on each end of the serial cable with the system name or ID for better tracking of cable and port connections on each system at the site.

Cabling the Workstation to the Multiplexer

To cable the multiplexer to an Indy or O2 system, follow these steps:

  1. Obtain the correct SCSI cable for your workstation. The Indy uses a 50-pin-to-50-pin cable (P/N 018-0689-001). The O2 uses a 50-pin-to-68-pin cable (P/N 018-8123-001).

  2. Connect the multiplexer to the workstation's SCSI port, as shown in Figure 2-2 or Figure 2-3.

    Figure 2-1. Multiplexer SCSI Cables

    Figure 2-2. Connecting the Multiplexer SCSI Cable to an Indy Workstation

    Figure 2-3. Connecting the Multiplexer's SCSI Cable to an O2 Workstation

  3. Attach the other end of the cable to the leftmost socket on the back of the multiplexer, as shown in Figure 2-4.

    Figure 2-4. Connecting the SCSI Cable to the Multiplexer

  4. Select an appropriate SCSI ID number by inserting a small screwdriver or other tool and rotating the arrow, as shown in Figure 2-5. Using SCSI ID 7 on early models of the multiplexer will cause the power indication LED to blink. Select another ID and the LED glows steadily with no blink.

    Note: The system disk in the Indy and O2 workstation is always SCSI target ID 1. Never select SCSI ID 1 for a multiplexer.

  5. If the multiplexer is the last SCSI device on the workstation's standard external SCSI port, terminate it properly by attaching the external SCSI terminator included in the multiplexer shipment. See Figure 2-5.

    Figure 2-5. Setting the Multiplexer SCSI ID

  6. Reboot the workstation.

After the workstation boots up, become superuser at the shell prompt to determine if the system recognizes the multiplexer. As the superuser, enter /sbin/cdscanbus and you should see something similar to this:

# /sbin/cdscanbus
Device type: 0x0
Vendor ID: 'SGI '
Product ID: '[productID]'
Firmware: '8640'
Vendor Unique:
30 30 32 33 34 31 34 34 00 00 00 00 00 00 00 00 00234144........
Device type: 0x9
Vendor ID: 'CenData '
Product ID: '[modelname]'
Firmware: `V[revisionlevel]'
Vendor Unique:
20 53 65 6e 64 20 4c 55 4e 20 00 00 00 00 00 00 .Send.LUN.......
Available SCSI ID numbers on bus 0: 2 3 4 6 7

If the multiplexer does not appear in the /sbin/cdscanbus listing, recheck all these items:

  • SCSI cable connections

  • SCSI terminator and ID

  • multiplexer power connection

  • proper software installation

You must have the multiplexer software drivers installed, or the cdscanbus command will not work. See the section “Troubleshooting” for additional troubleshooting tips.

Connecting the Multiplexer to Challenge, Onyx, and Origin Systems

You can plug the Challenge, Onyx, and Origin cables into the multiplexer in virtually any arrangement and map it with the IRISconsole software; see the IRISconsole Administrator's Guide (P/N 007-2872-nnn). For example:

  1. Select the appropriate serial cable (see Table 2-1 and Figure 2-6) for your system:

    Table 2-1. Serial Cables to Use With Servers



    Part number


    Challenge S




    Challenge DM/L/XL; POWER Challenge L/XL; Onyx and POWER Onyx



    25-pin-to-9-pin (male) connector

    Origin 200



    25-pin-to-9-pin (female) connector

    Origin2000 or Onyx2 deskside



    25-pin-to-9-pin (female) connector

    Origin2000 or Onyx2 rackmount




Note: All cable lengths are 25 feet (7.62 m) long.

  1. Each system requires a pair of serial cable connections to the multiplexer. Connect the 25-pin end of a serial cable to port 1 on the multiplexer and connect the second serial cable to port 2 (see Figure 2-7). Connect the cable from serial port 1 on the multiplexer as follows:

    • to the connector labeled System Console tty_1 on the I/O panel of the Challenge or Onyx (see Figure 2-8)

    • to the connector labeled System Console tty_1 on the Origin200 (see Figure 2-9)

    • to the connector labeled tty_1 Console on the rear of the Origin2000 and Onyx2 deskside systems (see Figure 2-10)

    • to the multimodule system controller (MMSC) Console (COM 1) port on Origin2000 and Onyx2 rack systems (see Figure 2-11)

      Note: If you already have a terminal connected to this port, move the terminal to another available connector on the BaseIO panel such as tty_2 (see Figure 2-11).

      Figure 2-6. Multiplexer Serial Cables

      Figure 2-7. Connecting the Serial Cables to the Multiplexer: Example

  • Cables 1 and 3 connect as illustrated for all systems except the Origin2000 and Onyx2 rack systems (see Figure 2-11).

  • The designated port for cables 2 and 4 varies for each system (see “Connecting the Multiplexer to Challenge, Onyx, and Origin Systems”).

    Figure 2-8. Location of Console Port (tty_1) on Challenge and Onyx Systems

    Figure 2-9. Location of Console Port (tty_1) on Origin200 Systems

    Figure 2-10. Location of Console Port (tty_1) on Origin2000 and Onyx2 Deskside Systems

    Figure 2-11. Connection to Rack

  1. Attach the connector from serial port 2 cable from the multiplexer as follows:

    • To the connector labeled Remote Sys Control SSE Use Only on the panel to the right of the I/O panel on the Challenge or Onyx. Figure 2-12 through Figure 2-15 show the location of the System Console tty_1 and Remote Sys Control SSE Use Only connectors.

    • To the connector labeled AUX port on the rear of the Origin200 (see Figure 2-16).

    • To the 9-pin serial connector on the rear of the Origin2000 and Onyx2 deskside system (see Figure 2-17).

    • To the Alternate Console (COM 5) connector on the MMSC (see Figure 2-11).

  2. Repeat these steps to connect additional Challenge, Onyx, and Origin systems to the multiplexer(s) used as part of the IRISconsole.

    Note: Do not run cables through areas that are electrically noisy, such as areas where large electric motors, welding apparatus, or X-ray machines operate. Bury outside wiring in conduit, as lightning strikes can damage the system.

    Figure 2-12. Cabling the Challenge L Server System Control Connectors

Note: Do not use the 8-pin powered serial connector for other uses in systems that have the IRISconsole multiplexer installed.

Figure 2-13. Cabling the Onyx Serial Connectors

Note: Do not use the 8-pin powered serial connector for other uses in systems that have the IRISconsole multiplexer installed.

Figure 2-14. Cabling the Challenge XL Serial Connectors

Note: Do not use the 8-pin powered serial connector for other uses in systems that have the IRISconsole multiplexer installed.

Figure 2-15. Cabling the Onyx Rackmount System Serial Connectors

Note: Do not use the 8-pin powered serial connector for other uses in systems that have the IRISconsole multiplexer installed.

Figure 2-16. Connecting the Multiplexer to the Origin200

Figure 2-17. Connecting the Multiplexer to the Origin2000 or Onyx2 Deskside System Second Serial Port

Connecting a Second Multiplexer

You can add a second multiplexer (see Figure 2-18) to the IRISconsole station using a 50-pin-to-50-pin SCSI cable (P/N 018-8123-001). This enables a single IRISconsole station to monitor a maximum of 16 individual systems.

  1. Remove the SCSI terminator from the first multiplexer and attach the SCSI cable.

  2. Plug the other end of the SCSI cable to first (or leftmost) connector on the rear of the second multiplexer (see Figure 2-18).

  3. Attach a terminator to the unused SCSI port on the second multiplexer.

    Figure 2-18. Connecting a Second Multiplexer


After the multiplexer is installed and operating correctly, it should never be powered off unless the system is shut down. If the multiplexer is powered off and then powered back on, restart all connections from the workstation to the multiplexer. Note that the multiplexer driver software recovers without rebooting the system.

If you do reboot the workstation, always be sure that the power is restored to the multiplexer before the system reboot begins.

Multiplexer Power LED

When the multiplexer is operating normally, the power LED glows steadily (see Figure 2-19). A blinking or unlighted LED on the multiplexer is probably a sign of malfunction.

Power-up tests are run each time the multiplexer is turned on, prior to execution of the run-time diagnostics and the main firmware. Failures result in a blinking or inactive power LED.

Check for these other possible causes:

  • Some early units blink when set with SCSI ID 7. Check to see if the multiplexer is set to ID 7 and change as necessary.

  • Confirm that both ends of the power supply connectors are properly installed.

  • Shut down the IRISconsole host system, then power cycle the multiplexer before powering on the workstation.

If none of these solutions resolve the problem, contact your service support organization for further assistance.

Figure 2-19. Location of Power LED on the Multiplexer

IRISconsole Malfunctions

Because the IRISconsole is a complex system of interconnecting units, you may have to check several likely sources to determine the cause of an intermittent malfunction.

Possible causes of intermittent malfunctions include

  • loose, broken, or bent pins on the SCSI or serial port connectors

  • two SCSI devices connected to the workstation with the same SCSI ID selected

  • improper or no termination of the SCSI bus

  • use of a tape drive not supplied by Silicon Graphics on the same SCSI bus as the multiplexer, which can cause SCSI bus timeouts that might affect multiplexer functionality

  • SCSI bus that exceeds two meters (6.6 feet), which may cause signal malfunction on the bus (count an additional 6 inches [2.4 cm]) of length for each device on the SCSI bus)

  • connecting the multiplexer to an optional SCSI board on the workstation

    IRISconsole is supported only on the workstation's built-in interface; attach the multiplexer only to the workstation's standard SCSI connector. Connection to optional SCSI interface cards is not supported.

For additional useful information on serial ports and configuration, see the reference (man) pages for the following:

  • inittab

  • gettydefs

  • ttytype

  • terminfo

  • stty

  • termio

  • cdstty

  • cdscanbus