Table of Contents
Advertisement
Lexicon, Inc.
MC-8 Serial Communications Protocol
4.1 Physical Layer
DB-9 RS232 Connector
MC-8
COM1
Transmit Data
2
Receive Data
3
5
Ground
9 Pin D-Shell (female)
Note: The wiring requirements for a 9 pin to 9 pin serial connection, are a male to female straight through cable.
4.2 Serial Port Driver
MC-8 serial port has been setup to operate as follows:
Operating Mode:
Baud rate:
Data Size:
Parity:
Stop Bits:
Hardware Handshaking:
4.3 Errors
The MC-8 will detect parity, framing and data overrun errors. If any of the physical layer errors are detected, the
complete packet is corrupted and the MC-8 will reset the transaction and begin to look for a start of packet byte.
4.4 MC-8 Receive Buffer
The MC-8 has an internal receive buffer. The buffer is 256 Bytes and will transmit a NAK packet with an error code
of DC_ERR_BUFFER_FULL to the HOST if the buffer is full. If the buffer is full, all data transmitted to the MC-8
will be ignored. Therefore, making the currently transmitted packet, if partially transmitted invalid.
4.5 MC-8 Hardware Verification
This test verifies the RS232 ports are working by comparing the transmitted signal (at pin 2) to the received signal
(at pin 3). The MC-8 transmits a known test signal just following a power up. The MC-8 monitors the serial port
receivers while transmitting the test signal. If the signals are the same, the test passes. In order to test this circuit,
RS232 Wraparound plug(s) are needed and must be installed at the female D9 connector(s) on the rear panel of the
MC-8 labeled "RS232". The wraparound plug shorts pins 2 to 3, allowing for the MC-8 to receive the signal it is
transmitting. Once installed, power cycle the MC-8 and verify the following message is displayed on the FPD:
This message is displayed for about 2 seconds before entering normal operating mode. If no messages are displayed,
then both wrap tests failed.
© 2003 Lexicon, Inc. All rights reserved.
9 Pin D-Shell (female)
2
3
5
9 Pin D-Shell (male)
Full Duplex
19.2K baud
8 bits (1 byte)
Odd
1
None
SERIAL PORT A PASSED
SERIAL PORT B PASSED
Printed on: 04/01/03
Host
Receive Data
2
2
Transmit Data
3
3
Ground
5
5
9 Pin D-Shell (male)
7 of 80
Advertisement
Table of Contents
