Urgent Fatek PLC Yarn Pattern Correction
Budget: ₹12,500 – ₹37,500 INR
Title: Fatek PLC Slub Yarn Pattern Fix — LFSR Randomization (WinProladder, urgent)
Description:
We have a thick-and-thin yarn machine controlled by a Fatek FBs-series PLC (WinProladder). It has a FBs-2DA analog output module that sends 0–10V speed commands to two VEICHI VFDs (DRAFT/1 and DRAFT/2) via registers D3840 and D3841 (0–4095 = 0–10V).
The problem: The current program uses a fixed step table that repeats every ~1.5m, causing a diamond pattern in woven fabric. The spec requires no repeat within 1000m.
What we need implemented — exact spec:
Two independent 16-bit LFSRs in ladder logic:
LFSR-1 for Roving 1: state in D100, mask K46080
LFSR-2 for Roving 2: state in D110, mask K53256
Period = 65,535 — never repeats within 1000m
No step table — direct LFSR scaling only:
thin_length = (LFSR_state MOD K86) + K15 → range 15–100mm.
Convert mm to scan-cycle count; store in D123 (Ch1) and D124 (Ch2).
RTC seeding at startup (M1902): seed D100 from D1018+D1019+D1020 (Fatek built-in clock). D110 = D100 + K1000. Never allow zero state.
Anti-repeat: if new value equals last output, add K3 and clamp to range.
Fixed slub length = 35mm via scan-cycle counter (K48 cycles at 10ms scan). Slub speed = DAC K3500. Thin speed = DAC K2048.
Speed ramp: each scan cycle, step D3840/D3841 toward target by K50 counts. Clamp 0–4095.
State machine: D126 flag (0 = thin, 1 = slub). Increment counters, switch state when target reached, call LFSR on each switch.
DRAFT/1 VFD fix: set P0.03 = 2 (analog AI1) and P0.01 = 1 (external terminal). Currently showing "not" error — no analog command is reaching it.
Deliverables: WinProladder project file with commented ladder logic + brief test procedure.
Full technical documentation with register map, hardware photos, and pseudocode is provided immediately on hiring. This is implementation only — design is complete.
Skills required: Fatek FBs PLC, WinProladder, VFD analog control, ladder logic (AND/XOR/SHR/DIV/MOD)
Description:
We have a thick-and-thin yarn machine controlled by a Fatek FBs-series PLC (WinProladder). It has a FBs-2DA analog output module that sends 0–10V speed commands to two VEICHI VFDs (DRAFT/1 and DRAFT/2) via registers D3840 and D3841 (0–4095 = 0–10V).
The problem: The current program uses a fixed step table that repeats every ~1.5m, causing a diamond pattern in woven fabric. The spec requires no repeat within 1000m.
What we need implemented — exact spec:
Two independent 16-bit LFSRs in ladder logic:
LFSR-1 for Roving 1: state in D100, mask K46080
LFSR-2 for Roving 2: state in D110, mask K53256
Period = 65,535 — never repeats within 1000m
No step table — direct LFSR scaling only:
thin_length = (LFSR_state MOD K86) + K15 → range 15–100mm.
Convert mm to scan-cycle count; store in D123 (Ch1) and D124 (Ch2).
RTC seeding at startup (M1902): seed D100 from D1018+D1019+D1020 (Fatek built-in clock). D110 = D100 + K1000. Never allow zero state.
Anti-repeat: if new value equals last output, add K3 and clamp to range.
Fixed slub length = 35mm via scan-cycle counter (K48 cycles at 10ms scan). Slub speed = DAC K3500. Thin speed = DAC K2048.
Speed ramp: each scan cycle, step D3840/D3841 toward target by K50 counts. Clamp 0–4095.
State machine: D126 flag (0 = thin, 1 = slub). Increment counters, switch state when target reached, call LFSR on each switch.
DRAFT/1 VFD fix: set P0.03 = 2 (analog AI1) and P0.01 = 1 (external terminal). Currently showing "not" error — no analog command is reaching it.
Deliverables: WinProladder project file with commented ladder logic + brief test procedure.
Full technical documentation with register map, hardware photos, and pseudocode is provided immediately on hiring. This is implementation only — design is complete.
Skills required: Fatek FBs PLC, WinProladder, VFD analog control, ladder logic (AND/XOR/SHR/DIV/MOD)