123Chapter 3. Communications Operations of the BHTChapter 3Communications Operations of the BHTThis chapter describes the communications operations of the BHT-7500/7500S/7500W—the spread-spectrum communication (for BHT-7500S/7500W only), IR communication,RS-232C interface specifications, the basic communications specifications, and thecommunications protocols—for data transfer with the host computer or other devices.3.1 Spread-Spectrum Communication (BHT-7500S/7500W only) ............................ 1243.1.1 Notes for Wireless Operations ...................................................................... 1243.1.2 RF-Related Parameters ................................................................................... 1243.2 Infrared Communication ....................................................................................... 1263.3 RS-232C Interface Specifications .......................................................................... 127[ 1 ] Interface Connector and Pin Assignment ............................................. 127[ 2 ] Interface Cable Connection .................................................................... 1283.4 Basic Communications Specifications and Parameters ..................................... 1293.4.1 Basic Communications Specifications .......................................................... 1293.4.2 Communications Parameters ........................................................................ 1313.5 Communications Protocols ................................................................................... 1323.5.1 BHT-protocol ................................................................................................... 132[ 1 ] Overview .................................................................................................. 132[ 2 ] Control Characters .................................................................................. 133[ 3 ] Basic Format of Transmission Messages .............................................. 135[ 4 ] Text Format .............................................................................................. 1363.5.2 BHT-Ir Protocol ................................................................................................ 138[ 1 ] Overview .................................................................................................. 138[ 2 ] Control Characters .................................................................................. 139[ 3 ] Basic Format of Transmission Messages .............................................. 141[ 4 ] Text Format .............................................................................................. 142