Bypass Modes; Figure 4-1 Data Flow In Through Mode - Compaq ES40CSLP Installation, User & Service Manual

_____________________________ Note____________________________
The internal system COM1 port should not be confused with the external COM1
serial port on the back of the system. The internal COM1 port is used by the system
software to send data either to the COM1 port on the system or to the RMC modem
port, if a modem is connected.
______________________________________________________________
You can set a local mode in which only the local channel can communicate with the system
COM1 port. In local mode the modem is prevented from sending characters to the system
COM1 port, but you can still enter the RMC from the modem.

Figure 4-1 Data Flow in Through Mode

System
SRM/AlphaBIOS
Consoles
Operating System

4.3.2 Bypass Modes

For modem connection, you can set the operating mode so that the data and control signals
partially or completely bypass the RMC. The bypass modes are snoop, soft bypass, and firm
bypass.
Figure 4-2 shows the data flow in the bypass modes. Note that the internal system COM1 port
is connected directly to the modem port.
_____________________________ Note____________________________
You can connect a serial terminal to the modem port in any of the bypass modes.
______________________________________________________________
The local terminal is still connected to the RMC and can still enter the RMC to switch the
COM1 mode if necessary.
COM1
RMC Modem
Port (Remote)
Modem Modem
RMC>
Remote Serial Terminal
or Terminal Emulator
Compaq ES40CSLP Rackmount System Installation/User/Service Guide 4–3
Remote System Management
DUART
COM1 Port
UART
RMC PIC
Processor
Modem Port
UART
UART
RMC COM1
Port (Local)
RMC>
Local Serial Terminal
(MMJ Port)
LJ-06636