Hello everyone, today plc247.com will write a tutorial for everyone to use Siemens S7 1200 PLC to control Hitachi NE S1 inverter through RS485 port using Modbus RTU Communication standard.
We need to use additional Siemens Module S7-1200 CB1241 (or S7-1200 CM1241) to connect to Hitachi NE S1 Inverter. Hitachi NES1 inverter has built-in 1 RS485 Port.
Siemens S7-1200 & Hitachi NE-S1 “Wiring Diagram”
+ Note: Use Terminal Resistor (120Ω) if communication distance is far
Hitachi NE-S1 Inverter Parameters Setting
In order for Siemens S7-1200 PLC to control Hitachi NES1 VFD with Modbus RTU, we need to set the communication parameters for Inverter NES1 as follows
+ Communication Parameters
+ Hardware SW5 Selection
Hitachi NE S1 Registers Address
Siemens S7-1200 Data Address & Mode Parameters
>>> VFD Run/Stop Coil Address = 1 + 0 = “1”
>>> VFD Forward/Reverse Coil Address = 1 + 1 = “2”
>>> VFD Reset Coil Address = 1 + 3 = “4”
>>> VFD Frequency Setting Word Address = 40001 + 1 = “40002”
>>> Output Frequency Word Address = 40001 + 4097 = “44098”
>>> Output Current Word Address = 40001 + 4098 = “44099”
>>> Output Voltage Word Address = 40001 + 4112 = “44113”
Siemens S7 1200 “Modbus RTU” Configuration
We need to set the communication parameters of the PLC to be the same as those set in the VFD
+ Siemens S7-1200 CB1241 Configuration
+ Modbus Data Blocks Create
S7 1200 “Modbus RTU” Example
+ Read/Write Auto Distribution
+ Communication Setting
+ Set Frequency Command
+ Motor Run/Stop “Control”
+ Motor Forward/Reverse “Control”
+ VFD Reset Command
+ Read Output Frequency
+ Read Output Current
+ Read Output Voltage
Project Video Tutorial
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Related Software and Documents
>>> Siemens S7 1200 Software Download
>>> Hitachi NE-S1 Manual PDF Download
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