My question is same as topic name:

How to check if Level 1 symbol is invalid?

I send wAAAA.TES\r\n as a watch command for example, but I don't receive anything from level 1 port. My expectation is some kind of messages like "Invalid Symbol" or I should check if AAAA.TES is valid before sending.

By the way, what is different between watch(w) and trade(t) command?
wMSFT and tMSFT...

Hello, you will get back a not found message. You could verify this in a telnet window as well.

wQPPG
Q,QPPG,,Not Found,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

As to the (t)Watch vs the (w)Watch, the w is to watch everything, trades, bids, asks, etc. The t watch will only pull through trades, this would allow for easier processing of the data stream if you did not need the bid and ask prices.

Tim

Edited by DTN_Steve_S on Jul 11, 2014 at 08:16 AM

In addendum to Tim's reply about the format of the Invalid symbol message, the

Q,QPPG,,Not Found,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Format is for the IQFeed 4.9 protocol only. If you have set your protocol to 5.0 or greater you will get a

n,QPPG

message instead to indicate an invalid symbol.

Thanks a lot, I'm using IQFeed 5.1 protocol. And I can see the n,QPPG now.

This solved my problem.