Connecting External Devices to VME Option Boards4-3014–001867Connecting Asynchronous Devices to aVAC/16 Asynchronous ControllerEach VAC/16 controller in your system supports 16 lines, with ports on attached8-line junction boxes (J-boxes). Each full-duplex line on a J-box can support anydata terminal device with an RS–232–C interface, such as an asynchronousterminal, a modem, or a serial printer. Figure 4–1 shows a VAC/16 junction box andthe 8 asynchronous device connectors on the J-box.5-ft cable to VAC/16(computer card cage)Junction boxDB25asynchronous deviceconnectorsFigure 4–1 VAC/16 Junction BoxYou can place your VAC/16 junction boxes on any convenient and safe horizontalsurface, such as a floor, desk, or table. You can also mount (secure with screws) aVAC/16 J-box to a wall or other surface panel. If you plan to mount a J-box on asurface, follow the special instructions for doing so in Appendix D before you connectthe J-box to your VAC/16 controller board or connect any external devices to theJ-box device connectors. If you do not plan to mount a junction box on a surface,continue with the next section in this chapter.Before you can connect asynchronous devices to a VAC/16 junction box, you need toattach the J-box to the controller board in your computer chassis. The followingsection illustrates this process for the Model 7411–KA VAC/16 assembly. To attach aModel 7411–K VAC/16 J-box and board assembly, refer to Appendix D for specialinstructions.
