This packet is used by the Secondary client to request a file search  that is performed by the currently connected Primary host.

This is the packet format

[0x1771][ Packet Data Length : 2 ][ Search Number : 4 ][ 00 : 1 ][ Minimum Line Type : 1 ][ 00 : 1 ][ FileType : 1 ][ 00 : 1 ][ Search String : S ][ 00 : 2 ]

The field marked "Search Number" is unique to each individual search and will be contained in all of the search results (177A) returned for this specific request.