Chapter 11 Data Communications Using Dc Code Transmission Control - Mitsubishi Electric MELSEC iQ-R Series User Manual

11
DATA COMMUNICATIONS USING DC CODE
TRANSMISSION CONTROL
The transmission control function controls (suspends, restarts) the transmission and reception of data between C24 and
target device by turning transmission control signals ON and OFF or by transmitting and receiving DC codes (DC1, DC2,
DC3, DC4), or informs the valid range for the data to the target device.
The transmission control function can be set for each C24 interface. C24 uses the transmission control function set by the
user to control data communications with target devices.
Set the transmission control function to match the specifications of the target device.
The table below lists C24 transmission control functions.
(: Valid, : Invalid)
Transmission
control function
DTR/DSR signal
*1
control
*2
RS/CS signal control
*2
CD signal control
*1
DC code control
*1 Refer to the following section when the full-duplex communication is used to communicate data with the bidirectional protocol.
Page 104 Processing when Simultaneous Transmission is Performed during Full-Duplex Communications
*2 Check the operation on C24 by the RS(RTS) signal, control contents of CS(CTS) signal, or CD terminal check designation.
MELSEC iQ-R Serial Communication Module User's Manual (Startup)
Precautions
When C24 is started, DTR/DSR signal control and RS/CS signal control are enabled.
How to change the transmission control method and DC code
Switching between DC code control and DTR/DSR control as well as changing of the DC code are set on "Transmission
control specification" of the parameter.
Navigation window  [Parameter]  [Module Information]  "Module Name"  [Module Parameter]  "Basic Settings"
 "Various control specification"
11 DATA COMMUNICATIONS USING DC CODE TRANSMISSION CONTROL
236
Type of control Interface that can be
controlled
232

DTR control
DSR control



DC1/DC3
transmission control
DC1/DC3 reception
control
DC2/DC4
transmission control
DC2/DC4 reception
control
Protocol that can be
controlled
422/485 MC Non
  
(ignore)
 
  
  
  
 
 
 
Remarks
Bi Pd
 
Cannot be used simultaneously with
DC control.
 
Select either one.
 
Normally controlled.
 
The cable wiring depends on whether
or not control is used.
With half-duplex communications,
control is necessary.
 
Cannot be used simultaneously with
DTR/DSR signal control.
Select either one.
 
 
 