that Windows Sockets programs require a compiler, such as Visual C++, in order to be executed. On UNIX machines, Berkeley Sockets is available on most of the common platforms.

5.The data sent to the Serial Adapter must be formatted appro- priately. A four-byte header precedes the user data that is sent. The contents of the four header bytes is as follows:

BYTE 1: Packet type

0= point-to-point (UDP or TCP), or 1= broadcast

BYTES 2 and 3: Packet length.

This is the length of the user data to be sent in this packet. The allowable range of lengths is 1-1456 bytes. The length bytes are arranged in network byte order.

BYTE 4: This byte is used to communicate RS-232 pin status to other Serial Adapters. Use a value of 0F (Hex) to ensure that the wired workstation and the Serial Adapter will communicate without interruption.

The pin status byte includes the following information:

Bit 0 is set if DTR is asserted on the sending side; set this to a value of 1 so that the Ethernet workstation will appear to have DTR asserted.

Bit 1 is set if DSR is asserted on the sending side.

Bit 2 is set if RTS is asserted on the sending side; set this to a value of 1 so that the Ethernet workstation will appear to have RTS asserted.

Bit 3 is set if CTS is asserted on the sending side.

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Proxima ASA 7910, 7911 manual