Agilent 33120A User's Guide

Chapter 4 Remote Interface ReferenceRS-232 Interface ConfigurationRS-232 Data Frame FormatA character frame consists of all the transmitted bits that make up asingle character. The frame is defined as the characters from the start bitto the last stop bit, inclusively. Within the frame, you can select thebaud rate, number of data bits, and parity type. The function generatoruses the following frame formats for seven and eight data bits.Connection to a Computer or TerminalTo connect the function generator to a computer or terminal, you musthave the proper interface cable. Most computers and terminals are DTE(Data Terminal Equipment) devices. Since the function generator is alsoa DTE device, you must use a DTE-to-DTE interface cable. These cablesare also called null-modem, modem-eliminator, or crossover cables.The interface cable must also have the proper connector on each endand the internal wiring must be correct. Connectors typically have9 pins (DB-9 connector) or 25 pins (DB-25 connector) with a “male”or “female” pin configuration. A male connector has pins inside theconnector shell and a female connector has holes inside the connector shell.If you cannot find the correct cable for your configuration, you mayhave to use a wiring adapter. If you are using a DTE-to-DTE cable, makesure the adapter is a “straight-through” type. Typical adapters includegender changers, null-modem adapters, and DB-9 to DB-25 adapters.Refer to the cable and adapter diagrams on the following page toconnect the function generator to most computers or terminals. If yourconfiguration is different than those described, order the 34399AAdapter Kit. This kit contains adapters for connection to othercomputers, terminals, and modems. Instructions and pin diagrams areincluded with the adapter kit.196