Communications Overview - CommTech FASTCOM SuperFASTCOM Hardware Reference Manual

6

COMMUNICATIONS OVERVIEW

HDLC/SDLC Protocol Modes
- Automatic flag detection and transmission
- Shared opening and closing flag
- Generation of interframe-time fill '1's or flags
- Detection of receive line status
- Zero bit insertion and deletion
- CRC generation and checking (CRC-CCITT or CRC-32)
- Transparent CRC option per channel and/or per frame
- Programmable Preamble (8 bit) with selectable repetition rate
- Error detection (abort, long frame, CRC error, short frames)
Bit Synchronous PPP Mode
- Bit-oriented transmission of HDLC frame (flag, data, CRC, flag)
- Zero bit insertion/deletion
- 15 consecutive '1' bits aborts sequence
Octet Synchronous PPP Mode
- Octet-oriented transmission of HDLC frame (flag, data, CRC, flag)
- Programmable character map of 32 hard-wired characters (00
- Four programmable characters for additional mapping
- Insertion/deletion of control-escape character (7D
Asynchronous (ASYNC) Protocol Mode
- Selectable character length (5 to 8 bits)
- Even, odd, forced or no parity generation/checking
- 1 or 2 stop bits
- Break detection/generation
- In-band flow control by XON/XOFF
- Immediate character insertion
- Termination character detection for end of block identification
- Time out detection
- Error detection (parity error, framing error)
BISYNC Protocol Mode
- Programmable 6/8-bit SYN pattern (MONOSYNC)
- Programmable 12/16-bit SYN pattern (BISYNC)
- Selectable character length (5 to 8 bits)
- Even, odd, forced or no parity generation/checking
- Generation of interframe-time fill '1's or SYN characters
- CRC generation (CRC-16 or CRC-CCITT)
- Transparent CRC option per channel and/or per frame
- Programmable Preamble (8 bit) with selectable repetition rate
- Termination character detection for end of block identification
- Error detection (parity error, framing error)
Extended Transparent Mode
- Fully bit transparent (no framing, no bit manipulation)
- Octet-aligned transmission and reception
Protocol and Mode Independent
- Data bit inversion
-1F )
H H
) for mapped characters
H