Logon Message Fields
| Tag | Field Name | Required | Description |
|---|---|---|---|
| 35 | MsgType | Y | A |
| 108 | HeartbeatInterval | Y | Client Heartbeat Interval (in seconds). |
| 141 | ResetSeqNumFlag | N | Indicates whether the FIX client and FIX server should reset sequence numbers. Absence of this field is interpreted as Do Not Reset Sequence Numbers (N).
|
The Logon must be the first message sent by the member after the TCP connection is established. EncryptMethod is ignored (FIX level encryption is not supported).
If the FIX client requires both parties to re-initialize sequence numbers (i.e. reset to 1), it may use the ResetSeqNumFlag (141) field sent on the Logon message. The FIX server will respond with a Logon with the ResetSeqNumFlag (141) field set to Y to confirm the initialization of sequence numbers. This feature is intended to help a FIX client manage an emergency situation. Re-initializing sequence numbers on a login should not be relied upon as a regular practice.
Cboe will wait one second after a Logon is received to ensure that no Resend Request messages are in flight from the member. A Heartbeat will be sent to indicate that the one second wait period has ended. Members should not send any orders prior to receiving this first Heartbeat from Cboe.
The IP Address of the member, the SenderCompId, SenderSubId and TargetCompId (defined in table above) and TargetSubId (TEST/PROD) will be validated. If validation fails the connection will be dropped without a Reject (to avoid corrupting the members sequence in the case that the member merely mistakenly connected to the wrong port).
If connection is unexpectedly broken, upon reconnecting the member may receive a login reply with a sequence number greater than expected. This means that in-flight messages were missed (likely important Execution Reports). The member should issue a Resend Request to retrieve the missed messages.
Similarly, Cboe will issue a Resend Request to the member for messages that it missed. The member may wish to send gap fill messages in place of new orders to avoid re-submission of potentially stale orders.
HeartbeatInterval must be specified by the member in the Logon message. This value will be clamped between 5 and 300 seconds and returned in the logon reply message. Cboe recommends using as low a value as the reliability and latency of your connectivity will allow.