TT® FIX Gateway

Logon (A)

Logon (A)

Logon (A) Message

Purpose

Used to establish a connection between a TT FIX Gateway and a third-party FIX acceptor

Message Direction

From TT FIX Gateways to a third-party FIX acceptor and then from a third-party FIX acceptor to TT FIX Gateways

Tag Directory

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Supported Tags

Tag # Field Name Req’d Data Type Comments
Component: Standard Header Y 35=A (MsgType)
96 RawData C String

Logon password

Condition: Will be sent when the TT FIX Gateway initiates a connection. The third-party FIX acceptor need not send this in the response.
98 EncryptMethod Y int

Method of encryption

As TT FIX Gateway does not support encrypted logons, you must set the value to 0 (None/Other).
108 HeartBtInt Y int

Heartbeat interval (seconds)
141 ResetSeqNumFlag N Boolean

Whether to reset the sequence numbers on both sides of the FIX session

Valid values include Y and N (default).
115 OnBehalfOfCompID N String

Assigned value used to identify firm originating message if the message was delivered by a third party, i.e. the third party firm identifier would be delivered in the SenderCompID field and the firm originating the message in this field.
128 DeliverToCompID N String

Assigned value used to identify the firm targeted to receive the message if the message is delivered by a third party, i.e. the third party firm identifier would be delivered in the TargetCompID (56) field and the ultimate receiver firm ID in this field.
354 EncodedTextLen N int

Byte length of encoded (non-ASCII characters) EncodedText (355) field.
355 EncodedText N String

Encoded (non-ASCII characters) representation of the Text (58) field in the encoded format specified via the MessageEncoding (347) field. If used, the ASCII (English) representation should also be specified in the Text (58) field.


Data length controlled by field EncodedTextLen(354)
Component: Standard Trailer Y

Message Notes

The Logon (A) message is used by a TT FIX Gateway to begin a new or continue an existing session with a third-party FIX acceptor.

The following data flow illustrates a typical logon sequence between a TT FIX Gateway and a third-party FIX acceptor:

  1. The TT FIX Gateway opens a socket connection to the third-party FIX acceptor.
  2. The TT FIX Gateway sends a Logon (A) message to the third-party FIX acceptor.
  3. If the third-party FIX acceptor detects any errors, it will respond with a Logout (5) message with the reason for rejection in Tag 58 (Text), and closes the socket connection.
  4. The third-party FIX acceptor examines the value of Tag 141 (ResetSeqNumFlag).
    • If Tag 141 (ResetSeqNumFlag) is set to N, the third-party FIX acceptor compares the value of Tag 34 (MsgSeqNum) in the Logon (A) message against its current sequence number.
      • If MsgSeqNum is less than the expected sequence number, the third-party FIX acceptor stops processing the logon attempt, sends a Logout (5) message as its response, and closes the socket connection.
      • If MsgSeqNum is greater than sequence number the third-party FIX acceptor expected, the logon process continues normally. However, after the logon process completes, the third-party FIX acceptor sends a Resend Request (2) message.
    • If Tag 141 (ResetSeqNumFlag) is set to Y, the third-party FIX acceptor expects the value of Tag 34 (MsgSeqNum) in the Logon (A) message to be 1.
      • If Tag 34 is not 1, the third-party FIX acceptor stops processing the logon attempt, sends a Logout (5) message, and closes the connection.
      • Otherwise, the logon process continues normally.
  5. The third-party FIX acceptor sends a Logon (A) message to the TT FIX Gateway.

TT FIX Price Gateway

The TT FIX Price Gateway will only support non-persistent FIX sessions. In other words, it will always send a Logon (A) message with Tag 34 (MsgSeqNum)=1 and Tag 141 (ResetSeqNumFlag)=Y when initiating a connection. As a result, the FIX session will terminate when the connection does.

TT FIX Order Gateway

When the TT FIX Order Gateway is started for the first time, it will send a Logon (A) message with Tag 34 (MsgSeqNum)=1. When there are unscheduled restarts, the standard FIX message sequence number negotiation will take place. After scheduled message sequence number resets, the TT FIX Order Gateway will send a Logon (A) message with Tag 34 (MsgSeqNum)=1.