Blink J1939, Руководство пользователя

Страница: 12 / 16

Via Montefeltro, 6 – 20156 Milano (MI) – Italy - 12 -
Tel. +39 (02) 3088583 – Fax +39 (02) 33406697
www.blinkmarine.com – info@blinkgroup.com
FOR REFERENCE ONLY
18. Heartbeat message (75h)
This command enables or disables the transmission of Heartbeat message. This
message is designed to indicate to other devices on the bus that this unit continues
to function.
Byte 0 04h Header bytes
Byte 1 1Bh
Byte 2 75h Heartbeat message
Byte 3 XXh XX:
00h Disabled (default)
01h Enabled
Byte 4 YYh YY: Period in milliseconds ÷ 10
From 05h (50ms) to FEh (2.54 sec)
Byte 5,7 FFh Not used
Example:
Direction Identifier Format Message Data
To
Keypad 18EF2100h Ext 04 1B 75 01 32 FF FF
FF Heartbeat enabled
with 500ms period.
Heartbeat generated message:
Byte 0 04h Header bytes
Byte 1 1Bh
Byte 2 F9h Heartbeat message
Byte 3 XXh XX: Message counter, incremented each
message sent
Byte 4 00 00 00 K5 K4 K3 K2 K1 Button state indicators
Each bit represents a button state
0: OFF
1: ON
Byte 5 00h
Byte 6 FFh Not used
Byte 7 21h Keypad identifier
Example:
Direction Identifier Format Message Data
From
Keypad 18EFFF21h Ext 04 1B F9 03 04 00 FF
21 Heartbeat
message with
button 3 pressed.
From
Keypad 18EFFF21h Ext 04 1B F9 03 10 00 FF
21 Heartbeat
message with
button 5 pressed