Kenwood TS-570D, TS-570S Instruction Manual

Also see for TS-570D, TS-570S: Instruction manual Instruction manual Adjustment guide Service manual

Contents

70l APPENDIXAPPENDIX: COM CONNECTOR PROTOCOLHARDWARE DESCRIPTIONThis transceiver uses a full-duplex, asynchronous, serialinterface for communicating through the male 9-PINRS-232C COM connector. Bytes are constructed with 1start bit, 8 data bits, and 1 stop bit (4800 bps can beconfigured for 1 or 2 stop bits). No parity is used. Thepinout and the pin functions of the COM connector areas shown below:COMRear panel viewRXD: Transmit data is serial data transferred from thetransceiver to the computer.TXD: Receive data is serial data transferred from thecomputer to the transceiver.GND: Signal ground pinRTS: This signal is applied to the transceiver. It is usedto inhibit transmit data from the transceiver when thecomputer is not ready to receive the data. Transmitdata is inhibited when the level is low.CTS: This signal is applied from the transceiver. It isused to inhibit transmit data from the computer whenthe transceiver is not ready to receive the data.Transmit data is stopped when the level is low.CONTROL OPERATIONMost computers handle data in the form of “bits” and“bytes”. A bit is the smallest piece of information thatthe computer can handle. A byte is composed of eightbits. This is the most convenient form for mostcomputer data. This data may be sent in the form ofeither serial or parallel data strings. The parallel methodis faster but more complicated, while the serial methodis slower and requires less complicated equipment. Theserial form is, therefore, a less expensive alternative.Serial data transmission uses time-division methodsover a single line. Using a single line also offers theadvantage of reducing the number of errors due to linenoise.Only 3 lines are required theoretically for control of thetransceiver via the computer:• Transmit data• Receive data• GroundFrom a practical standpoint, it is also necessary toincorporate some means of controlling when this datatransfer will occur. The computer and transceivercannot be allowed to send data at the same time! Therequired control is achieved by using the RTS and CTSlines.For example, the transceiver is placed into the transmitmode whenever the character string “TX;” is sent fromthe computer. The character string “TX;” is called acomputer control command. It tells the transceiver whatto do. There are numerous commands available forcontrol of the transceiver. These commands may beincorporated into a computer program written in anyhigh level language. Programming methods vary fromcomputer to computer; therefore, refer to the instructionmanuals provided with the terminal program andcomputer.123459 8 7 6123456789—Transmit dataReceive data—Signal ground—Receive enableTransmit enable——OutputInput——InputOutput—COMPin No.COM Pin Name(Ref.: Computer) Function(Ref.: Transceiver) I/ONCRXDTXDNCGNDNCRTSCTSNC