Connection via RS-232C

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Connection via RS-232C

Communication setting method

There are two connection points:

 

•Selecting the right RS-232C cable
There are several types of RS-232C cables, depending on the number of pins or the wiring method, etc. It is necessary to select a cable by checking the exact number of pins on the PC side and the PLC side, as well as the internal wiring published by the manufacturer.
For more information, refer to the manual for your PLC device.

 

•Match the communication parameters of RS-232C
The communication parameters on the PLC side and the PC side must match. The PLC side settings are made using physical DIP switches or configuration software, and the PC side settings are made in the "Communication Settings" dialog of each unit's properties.

 

 

In addition, there are two cases when connecting to multiple PLCs:

 

 

 

c_plc_0008

 

Communication is carried out by dividing it into multiple ports.

Each PLC communicates independently.

 

c_plc_0010

 

 

 

　c_plc_0009

 

PLC are connected via multi-drop with RS-422. However, the PLC must support multi-drop connections.

The PLCs are differentiated by folder network settings, and communication is also performed in order for each folder.

 

c_plc_0011

 

 

RS-232C common settings dialog

 

Communication Settings

c_plc_0012

 

 

•COMPort
Specify the communication port number to which the PLC is connected.

 

•Transmission speed
Specify the transmission speed (communication speed) between the PLC and the computer. If you want to set a transmission speed that is not in the list, enter it manually.

 

•Byte Size
Specifies the byte size.

 

•Stop bits
Specifies the type of stop bit.

 

•parity
Specifies the parity type.

 

•Other settings
If there are other PLC-specific settings.

 

Communication details

c_plc_0013

 

•Read timeout setting
Specifies the maximum time to wait for a response from PLC. If no data is received from PLC after this time has elapsed, reading will be stopped.

 

•Write timeout setting
Specifies the maximum waiting time for sending to PLC. If sending to PLC is not completed within this time, writing will be aborted.

 

•Retry count
When a communication error occurs, the system will retry the specified number of times.

 

•Minimum Communication Interval
Specifies the time the computer waits after receiving a device value from PLC before transmitting the next value.
This parameter needs to be adjusted for the Sharp JW series and Mitsubishi FX series. Normally, set it to "0".

 

•Error Handling
If you are using a conversion connector to connect to a USB cable, etc., the COM port may be locked and you may not be able to reconnect when you try to reconnect. In such a case, please check this box.