Automatic control function programming manual ladder language

Serial Lines
12.7.2.3 Xon/Xoff Flow Control
During reception, the transfer is monitored by sending control characters on the transmission channel.
As soon as character DC1 (Xon) is sent by the receiver, the sender is authorised to send. When the receiver sends
character DC3 (Xoff), the sender has a time equal to transmission of 20 characters to stop transmission.
Full duplex operation is impossible.
12.7.3 RS485 Standard
For software at index F or above.
With standard RS485, flow control is impossible. If standard RS485 is enabled by function comf(), the value of bit 0
of the «format» argument is not significant.
Signal RTS is high during transmission of a buffer and low during reception to set the RS232/RS485 interface adapters
to transmission or reception.
! CAUTION
The use of standard RS485 requires suitable wiring of the RS232/RS485 interface
adapters.
12.7.4 RS422 Standard
For software at index F or above.
With this standard, signal RTS remains high while the line is being used.
12.7.4.1 No Flow Control
No hardware or software signals are managed for transmission or reception.
Full duplex operation is possible.
12.7.4.2 Xon/Xoff Flow Control
During reception, the transfer is monitored by sending control characters on the transmission channel.
As soon as character DC1 (Xon) is sent by the receiver, the sender is authorised to send. When the receiver sends
character DC3 (Xoff), the sender has a time equal to transmission of 20 characters to stop transmission.
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