IB implemented new behaviour in their newest TWS 856.7 - after issuing more than 60 backfill requests withing 5 minutes, all subsequent requests fail with Error 162, \"historical data request pacing violation\".
\nNote that 60 requests means as little as backfilling one month back of 1-minute data for 12 symbols only (in one request you can ask for data maximum 5 days long).<\/p>\n
For details see: http:\/\/www.interactivebrokers.com\/cgi-bin\/discus\/board-auth.pl?file=\/2\/39717.html<\/a><\/p>\n