I have found that even if you honor the 50/sec limit TWS pacing errors will occur.? TWS may queue the messages and at a later time send them to the server.? The 50/sec limit applies to the interactions with the server, not TWS.? If the data farm connection is broken and you cancel or initiate new data subscriptions, TWS will queue these.? When the data farm connection is restored they are sent generating a pacing violation.? Vagaries in TWS internal operations can also cause pacing errors.? You can reduce the occurrence, but I don't think there is a way to absolutely prevent pacing errors assuming you are pushing the limit.? You should be prepared to reconnect if the three pacing error limit is hit.
