High-Frequency On-Balance Volume (OBV)

Query intraday minute-bar OBV (On Balance Volume) for A-share securities via the market data service.OBV accumulates volume on up-closes and subtracts on down-closes.line selects output: 'OBV' (cumulative volume) or 'MAOBV' (MA-smoothed, default M=30).codes: comma-separated security codes (e.g. '600000.SH,000001.SZ').interval: minute bar width — 1/3/5/10/15/30/60.starttime/endtime: 'YYYY-MM-DD HH: MM: SS' intraday range.