User's Manual

SECTION III OPERATION
SM 7063 07/97 3-32
3.16.2 Event Recorder Format
CDUs configured for “Event Recorder Protocol” conform to the data transfer protocol described in this
section.
3.16.2.1 Electrical Characteristics
Data is transmitted as follows:
1) RS-232/C Signal Levels
2) Asynchronous, serial
3) Baud Rate, Start Bit, Data Bits, Stop Bit, and Parity as configured via the Diagnostic PC. Standard
event recorders typically require these to be set to 1200 Baud, 1 Start Bit, 8 Data Bits, 1 Stop Bit, and
No Parity.
4) Messages are sent every 0.5 seconds, or immediately upon change of any data.
3.16.2.2 Data Transfer Protocol
Messages are transmitted per the following format:
Bit Position
Message Byte 7654 3210 Comment
Byte 1 Sync Byte 1010 1010 "AA" Hex
Byte 2 Sync Byte 1010 1010 "AA" Hex
Byte 3 Events 1 0abc defg Note 1
Byte 4 Events 2 0tuv wxyz Note 2
Byte 5 Pressure 0ppp pppp Note 3
Byte 6 CRC - HIGH Note 4
Byte 7 CRC - LOW Note 4
Refer to the following pages for a description of each individual bit assignment.