Upload
anish-shrivastava
View
2.390
Download
19
Tags:
Embed Size (px)
Citation preview
Modbus Communicationfor RTU Slaves
CompactLogix ControllerWith
1769 SM2 Module
By: Anish Shrivastava
Architecture
1769-L35E-CompactLogix5335E Controller
Modbus CableModbus Slaves
1769-SM2- Module
PCS ControllerPPI-402
SIPROTEC 4 7SJ61Multifunction Protection
Relay
Conzerv EM6400
AK-U0-RJ45-TB2P(RJ45 – RS485 Splitter)
Modbus RTU Network
Setting the Configuration Mode Switch in 1769 SM2 Module
Before installing the module, make sure its Configuration Mode Switch is correctly set.
SW1 Setting Description
CONT (Controller)back position
Default setting—The 1769-SM2 module uses the configurationdata downloaded from the controller on power-up and when thecontroller is placed in run mode.
PARAM (Parameter)front position
The 1769-SM2 module uses its internal parameter settings toconfigure the module.
SW2 Setting
Single Position (For Single drive per channel)
Multi-Drive Position (For Max 5 drives per channel or up 31 RTU slave devices per channel)
Select SW1 in Controller Position and SW2 in Multi-Drive Position.
Configuration and LogicM
od
ule
Con
fig
ura
tion
In
Log
ic
Mod
ule
Con
fig
ura
tion
In
Log
icConfiguration and Logic
Configuration and Logic1769-S
M2 M
od
ule
Con
fig
ura
tion
Data
For Channel
1
1769
-SM
2 M
odul
eCo
nfigu
ratio
n D
ata
Tabl
eConfiguration and Logic
Configuration and Logic
RTU Baud Rate Configuration RTU Format Configuration
e.g.: For baud rate 9600 bits/sec select value “2”.
e.g.: For None parity and 2 stop bits select value “3”.
Where The RTU format consists of threecomponents: data bits (8 data bits only), parity(None, Even or Odd), and stop bits (1 or 2).
For DSI I/O Config Select “5” for modbus RTU slave.
Use these data values to configure the configuration data table of SM2 module.
For RTU Rx Delay, RTU Tx Delay And RTU MSG Timeout select the values according to the load in controller and scan time of controller in such a way that the slave device has sufficient time to respond to the master.
Configuration and LogicLog
ic f
or
read
ing
Hold
ing
Reg
iste
r d
ata
of
RTU
Devic
es
Configuration and LogicLog
ic f
or
read
ing
Hold
ing
Reg
iste
r d
ata
of
RTU
Devic
es
Configuration and Logic
Path Format: Module Name, 2, Channel No.
Log
ic f
or
read
ing
Hold
ing
Reg
iste
r d
ata
of
RTU
Devic
es
Configuration and Logic
Refer to Notes
Log
ic f
or
read
ing
Hold
ing
Reg
iste
r d
ata
of
RTU
Devic
es
Notes
Slave Device ID: Can be configure for each slave device. (0-255)
Function Code: Can be differ according to the register type.(Such as 3-Holding Register, 4-Input Register)
Register Address and Length: May vary according to the slave device’s parameters.( For PCS Controller: Register Address is “3” and its data length is “1”.)
Please select the proper data mentioned above for slave devices otherwise communication fails.
For detailed information about these parameters please refer to the user manual of the particular slave device.
To check slave communication status and device parameters: use ModScan32 (3rd party software) if available.
AK-U0-RJ45-TB2P (RJ45 – RS485 Connector) Pin Out:
Clic
k H
ere
To S
ee E
xam
ple
References
1769 SM 2 Module User Manual
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um013_-en-p.pdf
THE END