JBL AV1 - SERIAL PROTOCOL DEFINITIONS Manual

Also see for Performance AV1: Brochure User guide

Contents

JBL Performance Series RS-232 Serial Protocol Definitions 9The AV1 will detect parity, framing, and data overrun errors. If any of the physical layer errors are detected,the complete packet is corrupted and the AV1 will reset the transaction and begin to look for a start ofpacket byte.4.4 AV1 Receive BufferThe AV1 has an internal receive buffer. The buffer is 256 Bytes and will transmit a NAK packet with an errorcode of DC_ERR_BUFFER_FULL to the HOST if the buffer is full. If the buffer is full, all data transmitted tothe AV1 will be ignored. Therefore, making the currently transmitted packet, if partiallytransmitted invalid.4.5 AV1 Hardware VerificationThis test verifies the RS232 ports are working by comparing the transmitted signal (at pin 2) to the receivedsignal (at pin 3). The AV1 transmits a known test signal just following a power up. The AV1 monitors theserial port receivers while transmitting the test signal. If the signals are the same, the test passes. In order totest this circuit, RS232 Wraparound plug(s) are needed and must be installed at the female D9 connector(s)on the rear panel of the AV1 labeled “RS232”. The wraparound plug shorts pins 2 to 3, allowing for the AV1to receive the signal it is transmitting. Once installed, power cycle the AV1 and verify the following messageis displayed on the FPD:SERIAL PORT A PASSEDSERIAL PORT B PASSEDThis message is displayed for about 2 seconds before entering normal operating mode. If no messages aredisplayed, then both wrap tests failed.5 Data Link LayerThe data link layer is used to define a transmission packet. The layer appends a header and tail thatencloses the transmitted application packet data. The data link header will contain the start of packet byteand count of bytes to follow. The data link tail will contain the end of packet byte.