This appendix provides information about serial cables to connect peripheral devices to the serial ports on your Serial Parallel Controller patch panel. You can purchase ready-made cables or make them yourself.
Two types of serial cables are described in this appendix:
This appendix also provides information about unrecognized cables.
If you are connecting a Hayes-compatible modem to your system using Serial Parallel Controller , you must obtain a modem cable with a male connector for the modem end and a male connector for the patch panel end. You can connect the modem cable to any of the eight serial ports on your patch panel. You can obtain the correct cable from most computer dealers or computer supplies stores.
In a serial modem cable, the pins in the connectors are wired straight through. This means that the pins function identically on the two connectors at both ends of the cable.
Data Terminal Equipment (DTE) typically includes terminals, personal computers, and workstations. Modems are a good example of Data Communications Equipment (DCE).
A modem cable connects a modem to your patch panel. Since DTE and DCE devices send and receive through different pins, their signals will not collide.
The following figure shows the wiring of a serial modem cable that enables the Serial Parallel Controller card to communicate with a Hayes-compatible modem. If you obtain a serial cable wired like the one shown, it will properly connect your patch panel and a Hayes-type modem. For the signal names of the pins, see "Patch Panel Pinouts" in Chapter 4.
Figure D-1 DTE to DCE
The cable wires of a null modem cable are not attached to the pins in the connectors in the same way as a modem cable. Terminals and printers use a null modem cable.
If you cannot purchase a ready-made null modem cable, you can make one by connecting a null modem converter to a modem cable as the following figure shows. The end that connects to your patch panel must be male. The gender of the connector at the other end of the cable depends on the peripheral device you are connecting to your patch panel.
Figure D-2 An Assembled Null Modem Cable
The serial null modem cable is designed for devices that send and receive data on the same pins. Terminals and printers are DTE devices - both expect to send data on pin 2 and receive it on pin 3. Because both devices are trying to send and receive on the same wire, these wires must be crossed.
If you are making your own null modem cable, you must connect the wire from pin 2 on the system unit end of the cable to pin 3 on the device end, and connect the wire from pin 3 on the system unit end of the cable to pin 2 on the device end. See the following figure for wiring your cable.
A null modem cable also disables certain features of a peripheral device by jumpering wire(s) from one pin to another pin on the same connector. The following figure shows pins 5 and 6 jumpered, and then connected to pin 20. Also, pins 4 and 8 are wired to each other. A cable wired like the one in this figure will connect your patch panel and a Wyse-compatible terminal.
If you have some other type of device, you will have to consult the manual for the device to determine whether jumpering is necessary and which pins are involved. For the signal names of the pins, see "Patch Panel Pinouts" in Chapter 4.
Figure D-3 Null Modem Cable
If your Serial Parallel Controller device driver recognizes a peripheral device, you can define it to your system. For the Serial Parallel Controller card to communicate with devices not supported by the Serial Parallel Controller device driver, you must inform your system about them by using the methods described in "Printer, Terminal, and Modem Software" in your Sun System & Network Manager's Guide.
But, first, you must select a serial cable that enables your card and the peripheral device to communicate. Because each device is different, there is no general rule for selecting or creating a serial cable. To obtain the correct cable, you will need to know which of the serial port pins are active. The manual for your terminal, modem, or printer should specify the active pins and what type of signal is sent or received on each pin. It should also specify what type of cable is required.
Also see "Patch Panel Pinouts" in Chapter 4 which identifies the active pins on the serial ports of your patch panel. Active pins are highlighted and the type of signal for each active pin is labeled.
Peripheral devices are cabled to the serial ports on your patch panel. This applies only to serial devices.
The manual or your dealer should have this information. Modems are generally DCE devices; most terminals and printers are DTE devices.
Begin by trying the cables with the pin configuration specified earlier in this appendix. These cables work with most devices.
Begin by trying the cables with the pin configuration specified earlier in this appendix. These cables work with most devices.
If these typical cable specifications do not work, see the manual for your peripheral device to determine which pins are active. Also see "Patch Panel Pinouts" in Chapter 4 to determine which pins are active for the serial ports on your patch panel.
You must wire the cable connectors according to the needs of both the peripheral device and the serial port on your patch panel. You might have to experiment to find a successful compromise.
