
E850-DTU(4440-GPRS) datasheet
Copyright ©2012–2018
,成都亿佰特电子科技有限公司
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Tran
smis
sion
ident
ifier
Prot
ocol
ident
ifier
Leng
th
Unit
ide
ntifi
er
Fu
nct
ion
co
de
Addr
ess
Regis
ter
length
Byt
es
Write value
Rece
ive
00 01
00 00
00 06
01
10
00 7B
00 17
Transm
ission
identifie
r
Protoco
l
identifie
r
Lengt
h
Unit
iden
tifie
Functi
on
code
Address
Register length
4.4.3 Heartbeat package
The heartbeat packet can be ASCII code or hex, the length of hex cannot be longer than 20 bytes,
and the length of ASCII code cannot be longer than 40 bytes. The first register of the heartbeat packet
is used to store the heartbeat packet data type. The value 0x0000 indicates that the heartbeat packet
is in hex format, and the value 0x0001 indicates that the heartbeat packet is in ASCII format. When
the value is 0x0000, the heartbeat packet value is 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09. The second register of the heartbeat packet is used to store the length of the heartbeat
packet value. The heartbeat packet value has a length of 10, corresponding to decimal 0x0A. As with
the custom registration packet registers, the unused heartbeat packet value registers can be filled
with "0" or not filled.
40147(0x0092)
40148(0x0093)
40149(0x0094) -- 40168(0x00A7)
Type
Length
Registration packet value
00 00
00 0A
00 01 02 03 04 05 06 07 08 09
00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00
Modbus RTU protocol write registration packet register: