Mitsubishi Electric MELSEC iQ-R Series User Manual page 164

■Data No. for connection designation (Un\G53)
• Designate the registration number of the data for connection used by C24 for the connection processing to the target device
in order to perform data communication.
The registration number is the number registered in C24.
• For details on the designation by program, refer to the following section.
(Page 190 Line connection)
■No-communication interval time designation (Un\G55)
• Designate the wait time until the line is closed when the data communication has ceased with the target device after the line
connection.
• C24 automatically performs the line disconnection processing when no data communication is performed with the target
device for a designated time.
The 'Connection' (X12) and the 'Modem initialization completion' (X10) are turned OFF and the 'Modem disconnection
completion' (X14) is turned ON when the line disconnection processing is performed.
■RS/CS control enable/disable designation (Un\G56)
• Designate whether or not the control to notify the data reception capability on the host station to the target side with the RS/
CS signal during data communication between C24 and modem/TA.
• This setting is for the interface designated for the modem connection channel indicated in the 'Modem connection CH
specification' (Un\G46).
The control of the other interface that does not use the modem function is performed by the settings in the 'DTR/DSR (ER/
DR), DC control designation' (Un\G147/307).
The overview of the RS/CS control is shown below.
● When transmitting data
• C24 detects the modem/TA data reception capability by ON/OFF of the CS (CTS) signal.
• When the CS (CTS) signal is ON, data transmission from C24 starts or continues.
When the CS (CTS) signal is OFF, data transmission from C24 is interrupted.
● When receiving data
• The C24 side reception capability is notified to the modem/TA by ON/OFF of the RS (RTS) signal.
• When the RS (RTS) signal is ON, C24 can receive data. Start/continue data transmission from the modem/
TA to C24.
When the RS (RTS) signal is OFF, C24 cannot receive data. Cancel data transmission from the modem/TA
to C24.
• C24 turns ON/OFF the RS (RTS) signal in the following conditions:
ON  OFF control of the RS (RTS) signal
C24 turns OFF the RS (RTS) signal when the free OS area for receive data storage becomes 64 bytes
(default) or less.
OFF  ON control of the RS (RTS) signal
C24 turns ON the RS (RTS) signal when the free OS area for receive data storage becomes 263 bytes
(default) or more.
■Modem function error code (Un\G545)
• Error code for an error occurred while the modem function is used or when abnormal signal ('Initialization/connection
abnormal completion' (X13)) turns ON is stored.
• For information on error codes, refer to the following section.
(Page 473 Error Code List)
7 COMMUNICATIONS BY THE MODEM FUNCTION
162
7.3 Specifications of Modem Function