Hi,

When I make this request:
"HTT,SY1017S70,20100623 000001,20100623 235959,0,093000,160000,1,SY1017S70,5000 "

I get this error message:
"SY1017S70,E,Invalid symbol.,"

Thats odd. It is a proper symbol name, and is listed in the mktsymbols_v2.zip file as follows:
SY1017S70 SY JUL 2010 P 70.000 OPRA OPRA IEOPTION

Also, I note that HTT sometimes returns "E,!NO_DATA!" for valid symbols when there were no ticks for the day requested (for example, same as above using symbol GILD1017S38). Why return an error message in this case?

Thanks,
David.

David, the history servers will return an Invalid symbol message for valid symbols if there is no data available in the system for that symbol.

It will return the NO_DATA message if there is data available but none that meet the criteria for your request.

In the first case, since your system already knows that it is a valid symbol, you can treat this exactly the same as the second case (although you also know that no other requests for that symbol are going to return data either).