Advantech ADAM-5511 Manual page 280

Read Modem Control Register (MCR)
Set Modem Control Register (MCR)
Read from specified port modem control register
Set from specified port modem control register
int port_get_modem_control_status(int portno)
int port_set_modem_control_params(int portno, int MCRparams)
portno
MCRparams
Read MCR:
0x00XX :
0xFF00
Write MCR:
0x0000
0x0001
0xFF00
The specified port number
Modem control register parameter
(see UART Register Description Table)
modem status
: bad command or parameter
: write MCR success
: read back error
: bad command or parameter