CHAPTER 9: DIP-Switch Settings

Switch #2

Flow Control - &E4/&E5

(Asynchronous Mode/Leased Line/Dial-Up)

With Hardware Flow Control, the modem uses its RS-232C/V.24 interface to control the flow of data from the computer or terminal to which it is attached. The CTS signal on Pin 5 of the RS-232C/V.24 is brought low to stop the flow of data, and is brought high to restart it. Place DIP-Switch #2 in the UP position to enable Hardware Flow Control (&E4). Xon/Xoff Flow Control (&E5) is another flow control method. Xon/Xoff characters in the data dictate the start and stop of data flow from the computer or terminal. Place DIP-Switch #2 in the DOWN position to select Xon/Xoff Flow Control.

Hardware Flow Control (&E4)

=

Switch #2 UP

Xon/Xoff Flow Control (&E5)

=

Switch #2 DOWN

Factory Default Setting

=

UP

Switch #2

SDLC/BSC Option

(Synchronous Mode/Leased Line/Dial-Up)

Synchronous Data Link Control (SDLC) and Binary Synchronous Control (BSC) are two error correction protocols used in the IBM Mainframe environment. Place DIP-Switch #2 in the UP position to enable SDLC mode, and place DIP-Switch #2 in the DOWN position to enable BSC mode.

SDLC Mode

=

Switch #2 UP

BSC Mode

=

Switch #2 DOWN

Factory Default Setting

=

UP

129

Page 130
Image 130
Black Box MD1640A, MD1641A manual 129