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OpenReadout

WinWCP .wcp

WinWCP (Strathclyde Electrophysiology Software) records whole-cell patch-clamp sweeps to .wcp files. OpenReadout returns one trace with a channel per signal and a sweep per record, with each record’s time, status and type.

Derived from Neo’s WinWcpRawIO (BSD-3, read as documentation and run as a reference reader) and two public files (file versions 8 and 9, WinWCP 5.3.7). Provenance: docs/provenance/winwcp.md.

Crate: openreadout-ephys, format id winwcp (WINWCP_FORMAT_ID), extension wcp, reader WinWcpReader, dataset WinWcpDataset (open, open_input, wcp). Detection: the file starts with VER= and the header holds NC= and NBD= lines (looks_like_wcp) → definite; a .wcp name alone → extension only.

Layout (parse_wcp → WcpFile)

  • Text header (WCP_HEADER_LEN = 1024 bytes): KEY=value lines separated by CR LF, decimal commas (DT=6,005E-005), kept verbatim in header. Used: VER (version), NC channels, NR records, NBA and NBD analysis and data sectors per record (analysis_sectors, data_sectors; WCP_SECTOR = 512 bytes), ADCMAX (adc_max), and per channel c YNc name, YUc unit, YGc gain in V per unit, YOc position in the sample frame, YZc zero level (WcpChannel: name, unit, gain_v_per_unit, offset_in_frame, zero_level); RTIME (version 9) / CTIME, VERPROG, ID.
  • Records: record k starts at 1024 + k × (NBA + NBD) × 512 (record_offset, record_bytes). Its analysis header (WcpRecord): 8 characters of status (ACCEPTED), 4 of type (TEST), then float32 group number, time recorded (s since the first record), sampling interval (s) and one full-scale voltage per channel (status, record_type, group, time_s, interval_s, vmax). Its data: NBD × 512 bytes of int16 frames of NC samples (samples = NBD × 512 / 2 / NC per channel).
  • Values (gain): raw × VMax(record, channel) / ADCMAX / YG, in the channel’s unit (Neo’s formula; each record’s own VMax, constant in both public files). YZ is reported (extra.zero_level_adc), not subtracted, as Neo does.
  • Sample rate: 1 / the median of the records’ float32 intervals (interval_s; Neo’s rule).
  • Channel columns: YO gives each channel’s position in a frame when the offsets are a permutation of 0…NC−1; otherwise header order, with a channel_offsets warning.
  • recorded_at: RTIME (else CTIME), dd/mm/yyyy hh:mm:ss → local time without zone.

Mapping

One trace record with one channel per signal (dtype int16, scale = record 0’s gain), one sweep per record (MAX_WCP_RECORDS), start_s 0; extra: file_version, application (WinWCP) and application_version (VERPROG), recorded_at, comment (ID), sweep_starts_s (each record’s time recorded), record_status, record_type, record_group; channel extra: zero_level_adc, gain_v_per_unit, vmax_v. Reads are capped at MAX_WCP_READ samples per channel; at most MAX_WCP_CHANNELS channels.

check finding codes

truncated, bad_gain (errors); channel_offsets, extra_bytes, bad_interval (warnings); rejected_records (info).

Observed corpus values

id version channels records × samples rate
winwcp-file-winwcp-1 8 Im (pA), Vm (mV) 16 × 49,920 16.65 kHz
winwcp-file-winwcp-2 9 (5.3.7, RTIME 2019-05-21) Vm0 (mV), Icom0 (pA) 20 × 39,680 20.08 kHz

Vocabulary (every public identifier in crates/openreadout-ephys/src/winwcp/ must appear here)

identifier meaning
WinWcpReader, WINWCP_FORMAT_ID, WinWcpDataset, open, open_input, wcp entry points
WcpFile, parse_wcp, header, version, adc_max, channels, records, analysis_sectors, data_sectors, samples, file_len, findings, record_bytes, record_offset, gain, interval_s, recorded_at the file
WcpChannel, name, unit, gain_v_per_unit, offset_in_frame, zero_level a channel
WcpRecord, status, record_type, group, time_s, vmax a record’s analysis header
WCP_HEADER_LEN, WCP_SECTOR, MAX_WCP_CHANNELS, MAX_WCP_RECORDS, MAX_WCP_READ, looks_like_wcp constants, limits, detection

How this reader was derived, file by file: provenance log.