37
UM-HDRM(G) 4/17
bAuD RATE
19200 bps
DATA bITS
8
pARITY
NONE
START bITS
1
STOp bITS
1
fLOW CONTROL
NONE
TAbLe 12
PHYsICAL AND DATA LINk LAYer
The HDRM communicates via RS422 interface
using the following port settings (Table 12).
CoMMUNICATIoN ProToCoL
The HDRM protocol uses packets based on the NMEA message format. This consists of an
ID, comma delimited fields, a checksum field and a two-character checksum. A response
message is transmitted from the HDRM upon receiving a message. It will either be the spe-
cific response for the command, a general DSACk response, or a DSNAk response if the
command is not recognized or the packet is invalid.
The System Test can be run at power ON, when initiated by a bIT serial command, when
initiated by the user from the I-bIT menu, or System Test can run continuously. Table 11
shows when each test is run, in various bITs: power-up (p-bIT); Initiated Serial and Initi-
ated Menu (I-bIT), and Continuous (C-bIT).
SYSTEM TEST NAME
pOWER up INITIATED
SERIAL
INITIATED
MENu
CONTINuOuS
RAM ERROR
YES
YES
YES
NO
ROM ERROR
YES
YES
YES
NO
EEp ERROR
YES
YES
YES
NO
COMM ERROR
NO
NO
NO
YES
SYSTEM CLOCk ERROR
YES
YES
YES
NO
VIDEO ERROR
NO
NO
YES
NO
buTTON ERROR
NO
NO
YES
NO
DEVICE (1) ERROR
YES
YES
YES
NO
DEVICE (2) ERROR
YES
YES
YES
NO
DEVICE (3) ERROR
YES
YES
YES
NO
DEVICE (4) ERROR
YES
YES
YES
NO
DEVICE (5) ERROR
YES
YES
YES
NO
DEVICE (7) ERROR
YES
YES
YES
NO
DEVICE (8) ERROR
YES
YES
YES
NO
Events performed at p-bIT, I-bIT and C-bIT
TAbLe 11
CoMMUNICATIoN ProToCoL
