Advertisement
COMMUNICATION PROTOCOL
Communication Protocol
Select the Communication Protocol of RS232 or RS422 from the Utility Menu > COMM. The
DVR 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 mes-
sage is transmitted from the DVR upon receiving a message. It will either be the specific
response for the command, a general DSACK response, or a DSNAK response if the com-
mand is not recognized or the packet is invalid.
The System Test may 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 may run continuously. Table 8
shows when each test is run, in various BITs: Power-up (P-BIT); Initiated Serial and Ini-
atiated Menu (I-BIT), and Continuous (C-BIT). This Table is a repeat of page 38, Events
Performed at Built-In-Test (BIT).
Events Performed at P-BIT, I-BIT and C-BIT
SYSTEM TEST NAME
RAM ERROR
ROM ERROR
EEP ERROR
DVR ERROR
KEY ERROR
PWR ERROR
Physical and Data Link Layer
The DVR communicates via RS232 or RS422 interface using the following port settings
(Table 9).
POWER UP
INITIATED
SERIAL
YES
YES
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
Table 8. BIT EVENTS
INITIATED
MENU
YES
YES
YES
NO
YES
YES
BAUD RATE
DATA BITS
PARITY
START BITS
STOP BITS
FLOW CONTROL
Table 9. PORT SETTINGS
MPC-ML2DVR-UM(B) 3/2019
CONTINUOUS
NO
NO
NO
YES
NO
NO
19200 bps
8
NONE
1
1
NONE
49
Advertisement
