EPA SM-Ethernet, Руководство пользователя

Страница: 114 / 133

SM-Ethernet User Guide
113
Issue: 7
Sa
fety
in
fo
rm
at
io
n
In
trod
uc
tion
Me
cha
nical
in
stal
lat
ion
El
ec
tric
al
ins
tall
ati
on
Get
tin
g
st
arted
Pr
ot
oc
ol
s
We
b p
ag
e
ba
si
cs
FTP
/c
ustom
pa
ge
s
App
lic
ati
ons
Se
cu
rity
Di
agn
os
tic
s
Adva
nce
d
feat
u
res
Q
uick
re
fe
re
nc
e
Glossa
ry
o
f
te
rm
s
In
de
x
12.6.2 FC03-Read multiple registers
This function code allows a contiguous array of registers to be read. The server (drive)
imposes an upper limit on the number of registers that may be read and If this is
exceeded the server will issue an exception code 2.
12.6.3 FC06-Write single register
Writes a value to a single 16 bit register. The normal response is an echo of the request
after the register contents have been successfully written. The register address can
correspond to a 32 bit parameter but only the least significant 16 bits of data will be
returned.
Table 12.5 Client request message Table 12.6 Server (drive) response
message
Byte Description Byte Description
0
Server destination node
address, 0 is broadcast.
0 Server source node address.
1 Function code 0x03. 1 Function code 0x03.
2 Start register address MSB. 2
Length of register data
(bytes).
3 Start register address LSB. 3 Register data 0 MSB.
4 Number of 16 bit registers MSB. 4 Register data 0 LSB.
5 Number of 16 bit registers LSB. 5 Register data 1 MSB.
6 Register data 1 LSB.
For each byte in the PDU message, the MSB is transmitted first, followed by the LSB.
If only one 16 bit register of a 32 bit register address is read the server returns the least
significant word.
For multiple registers, the register data will be returned in ascending order, beginning
with the start register address.
NOTE
NOTE
NOTE
The Modbus CRC bytes are not required when using TCP/IP due to the ethernet frame
providing the error checking.
NOTE
Table 12.7 Client request message Table 12.8 Server (drive) response
message
Byte Description Byte Description
0
Server destination node
address, 0 is broadcast.
0 Server source node address.
1 Function code 0x06. 1 Function code 0x06.
2 Register address MSB. 2 Register address MSB.
3 Register address LSB. 3 Register address LSB.
4 Register data MSB. 4 Register data MSB.
5 Register data LSB. 5 Register data LSB.
To write 32 bits of data to a 32 bit register address, the extended data type must be
used (see section 12.6.1
Extended data types on page 112).
For each byte in the PDU message, the MSB is transmitted first, followed by the LSB.
NOTE
NOTE
The Modbus CRC bytes are not required when using TCP/IP due to the ethernet frame
providing the error checking.
NOTE