RS422/485 SERIAL INTERFACE PLUS
MM
SS
NN
Figure 4-4. Header E2 in Shared Mode.
Header E5 is used to control the RS-485 enable/disable functions for the driver circuit. One of the unique features of the RS422/485 Serial Interface Plus is its ability to be RS-485 compatible without the need for special software or drivers. This is especially useful in Windows, Windows NT, and OS/2 environments where the lower level I/O control is abstracted from the application program. This means that the user can effectively use the RS422/485 Serial Interface Plus in a RS-485 application with existing software drivers.
TX
AUTO RTS 422
Figure 4-5. This jumper is in the “422” position. Note that the modem control outputs are only valid when Header E5 is in the 422 mode.
AUTO | Driver automatically Enabled/Disabled |
RTS | Driver Enabled by UART RTS signal |
422Driver always Enabled
Figure 4-6. Header E5.
