Reception; Baud Rate; Summary; Sdn Interface Card - HP M2350A Service Manual

Understanding the Computer Module
The Function Cards
Data Transfer
Data is passed directly between the MPB and the interface which converts the transmit data
into serial data for either port 0 or 1 and serial receive data to parallel format.
Transmission
The data is loaded into the MPB Interface's RAM. The processor reads this data and writes it
into the serial port register. Port 1 uses the microprocessor's internal serial port register and
port 2 uses the UART. Data is then shifted-out of the registers at the chosen baud rate. The
RS232/422 drivers transform the TTL voltages into those suitable for the RS232 and RS422
transmission.
Reception
The interface is switched between either RS232 or R'S422 operation. The received RS232 and
RS422 voltages are transformed to 'ITL levels The data is written into the serial port input
registers for each port. The data is then buffered in the MPB Interface RAM before being
output to the MPB.
Baud Rate
The interface can be switched, under control of application software in the DEVXONFIG
command of the session, to accommodate a range of devices that use fixed data transmission
speeds. The baud rates available for the interface are as follows:
150, 300, 600, 1200, 2400, 4800, 9600, 19200, and 38400 (2nd port only).
Summary
n
Provides 2 serial ports using 8051 microprocessor with an additional ,UART.
n
Communicates directly between external devices and the MPB.
n
Translates MPB parallel data broadcast on an 16-bit bus to serial data over RS232 and RS422
standard interfaces.
n
Translates received serial data from either RS232 or RS422 to MPB parallel data.
n
Switchable baud rate, under control of application software.
SDN Interface Card
The SDN Interface card is the interface between the system, via the Utility CPU, and the Serial
Distribution Network, and has the function of transmitting and receiving data to and from the
SDN. Only one SDN Interface card may be used with each HP Component Central Monitor.
Specifications
Identifier Port.
16 bit
Internal Connector.
96 pin
External Connectors
Upstream SDN connector
Downstream SDN connector
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