SOURCENIC - Gets data from multicast source (i.e. rumeL box) from UDP port
            and sends data to file/pipe

<OUTPUT> Output pipe (header = header filled by m_initialize with SB data) <ADDRESS> Multicast address to receive data from (numerical in quotes) <INTERFACE> IP address of interface to receive multicast data into (numerical in quotes)

Reads from the UDP port are blocking. All data appearing at <PORT> will be acquired, there is no check for which source it's coming from.

Socket buffer size is set internally to try to get /SBUFSZ, however, for RHEL4U2 the max is set in the kernel to 256k. You can change the max value to something more reasonable for high speed acquisition with the following command:

/sbin/sysctl -w net.core.rmem_max=1048576

You can check to see what the current value is with the following command: /sbin/sysctl net.core.rmem_max

(this sets it to 2MBytes). I have demonstrated the above value to be adequate for gigabit ethernet acquisition WITHOUT anything else running on the same CPU.

SWITCHES: /DEBUG - debug info level /SDDSMODE=n - 1=raw_packets, 2=data_only, 3=header_only /FC= - specify header format code as SB,SI,CB,CI (SB default) /XD= - specify header abscissa increment (default 1.0) /PORT=n - UDP port # to receive data (default = 29495, the SDDS port) /PRANGE=n - range of ports to use starting at <PORT> (i.e. if requested port is unavaliable) /TL=n - # of bytes to transfer each pass. For SDDS data this must be set to 1080 (the default) /SBUFSZ=n - Desired socket buffer size in bytes. Default=10M. Kernel may or may not allow this size (see notes above) /NUMPKTS= - Exit after output of specified number of SDDS packets

CONTROL WIDGETS: 1. L:exit - setting to any value other than 0 forces primitive to exit 2. D:pktcnt - received packet counter

REVISION PROGRAMMER DESCRIPTION -------- ---------- ------------------------------------- 07-Feb-2007 dkc baseline 27-Nov-2007 rdh added output modes/switches/widgets

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