PLC 審查問題對應階梯圖
單車道雙向通行控制 —— 15 項問題的修正梯形圖與完整重構程式
| 對應文件： | 《PLC 梯形圖程式設計審查報告》（2026-07-05） |
| 內容範圍： | 問題 1–11 與建議 12–15 之修正階梯圖 |
| 附錄： | 修正後完整程式 Rung 1–23 |
| 文件日期： | 2026 年 7 月 6 日 |
圖中符號採 IEC 慣用之 NO／NC 接點、線圈與功能方塊表示法；
變數名稱沿用原程式，狀態常數與 I/O 對照見第 1 節。
狀態常數與變數
| 值 | 狀態常數 | 變數 | 意義 |
|---|---|---|---|
| 0 | INIT |
INPUT1 / INPUT2 |
A 端／B 端光電感測器 |
| 1 | IDLE |
PB_RESET |
故障復歸按鈕 |
| 2 | FWD |
OUTPUT_1 / OUTPUT_2 |
車道占用燈／故障燈 |
| 3 | HOLD |
STATE |
狀態暫存器（INT） |
| 4 | REV |
M_INPUT1_Rise 等 |
邊緣旗標（單一掃描週期） |
| 5 | FAULT |
FaultLatch / SensorStuck |
故障閂鎖／感測器卡住 |
| 6 | REV_HOLD（新增） |
TON_1/2A/2B/3 |
10 s 駐留／5 min 卡住／60 s 逾時 |
梯形圖符號圖例
at (0.9,0) cno=VAR; at (2.4,0) NO 常開接點：變數為 1 時導通; at (0.9,-1.0) cnc=VAR; at (2.4,-1.0) NC 常閉接點：變數為 0 時導通; at (0.9,-2.0) cpe=VAR; at (2.4,-2.0) 上升緣接點（OSR/R_TRIG）：0\(\to\)1 的那個掃描週期導通一次; at (0.9,-3.0) coil=VAR; at (2.4,-3.0) 輸出線圈：rung 導通時 ON，斷開時 OFF; at (0.9,-4.0) scoil=VAR; at (2.4,-4.0) 設定線圈（Latch）：導通後保持 ON，需 U 復歸; at (0.9,-5.0) ucoil=VAR; at (2.4,-5.0) 復歸線圈（Unlatch）：導通時將閂鎖變數復歸為 OFF; (0.9-1.05,-6.3-0.4) rectangle (0.9+1.05,-6.3+0.4); at (0.9,-6.3+0.21) EQU; at (0.9,-6.3-0.15) STATE=FWD; (0.9-1.23,-6.3) – (0.9-1.05,-6.3); (0.9+1.05,-6.3) – (0.9+1.23,-6.3);
at (2.4,-6.3) 比較方塊：條件成立（相等）時導通，作為接點使用; (0.9-1.15,-7.7-0.45) rectangle (0.9+1.15,-7.7+0.45); at (0.9,-7.7+0.24) MOV; at (0.9,-7.7-0.15) IDLE \(\to\) STATE; (0.9-1.33,-7.7) – (0.9-1.15,-7.7); (0.9+1.15,-7.7) – (0.9+1.33,-7.7);
at (2.4,-7.7) 傳送方塊：rung 導通時將來源值寫入目的暫存器; (0.9-1.05,-9.3-0.62) rectangle (0.9+1.05,-9.3+0.62); at (0.9,-9.3+0.4) TON_3; at (0.9-0.82,-9.3+0.16) IN; at (0.9+0.84,-9.3+0.16) Q; at (0.9,-9.3-0.36) PT: T#60s; (0.9-1.23,-9.3) – (0.9-1.05,-9.3); (0.9+1.05,-9.3) – (0.9+1.23,-9.3);
at (2.4,-9.3) 通電延遲計時器：IN 持續導通達 PT 後 Q = 1；IN 斷開立即復歸;
問題與 rung 對照
| 問題 | 摘要 | 完整程式對應 rung（第 5 節） |
|---|---|---|
| 問題 1 | INIT 無出口（上電死鎖） | R3 |
| 問題 2 | Reset 無條件回 IDLE | R21 |
| 問題 3 | REV 過早結束 | R13、R16、R18 |
| 問題 4 | 計時器 Q 未限定狀態 | R17、R18 |
| 問題 5 | 邊緣偵測標籤不一致 | R1、R2（改用內建邊緣） |
| 問題 6 | 逾時應進 FAULT | R14、R15 |
| 問題 7 | REV 不點占用燈 | R22 |
| 問題 8 | 兩端同時來車死鎖 | R9–R11 |
| 問題 9 | 卡住偵測共用計時器 | R4–R6 |
| 問題 10 | 故障優先權與復歸耦合 | R8、R21 |
| 問題 11 | 多車跟進（車輛計數） | 選配（見 3.6 節） |
| 建議 12–15 | 內建邊緣、集中化、命名、按鈕取緣 | R1、R2、R21 及全篇 |
嚴重問題修正階梯圖（問題 1–5）
問題 1：INIT 狀態沒有出口 —— 上電死鎖
原程式沒有任何 rung 處理 STATE = INIT（上電預設值 0）。 修正：新增一條初始化 rung，等待兩支感測器皆淨空後才進入 IDLE； 若上電時感測器被遮斷，系統會停留在 INIT 直到車道淨空，不會誤動作。
修正 新增 rung：INIT 且 A、B 皆淨空 \(\to\) IDLE
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=INIT; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cnc=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
若平台提供首次掃描旗標（如 _SYSVA_FIRST_SCAN），亦可改以首次掃描觸發並在 感測器遮斷時直接閂鎖故障；上圖的「等待淨空」寫法較簡單且不需額外旗標。
問題 2：Rung 24 —— PB_RESET 無條件強制回 IDLE
現況 原 Rung 24：按鈕電平直接寫入，任何狀態都會被覆寫
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=PB_RESET; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 加上三重限定：按鈕取上升緣、僅在 FAULT 狀態、且故障已成功解閂
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cpe=PB_RESET; (1.68,0) – (1.97,0); (3.2-1.05,0-0.4) rectangle (3.2+1.05,0+0.4); at (3.2,0+0.21) EQU; at (3.2,0-0.15) STATE=FAULT; (3.2-1.23,0) – (3.2-1.05,0); (3.2+1.05,0) – (3.2+1.23,0);
(4.43,0) – (5.02,0); at (5.4,0) cnc=FaultLatch; (5.78,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
如此車輛通行中誤按復歸不再影響狀態機；故障未排除（FaultLatch 仍為 1）時 按住按鈕也不會造成 STATE 每週期震盪。
問題 3：Rung 16 —— REV 的離開條件錯誤
現況 原 Rung 16：B 下降緣即回 IDLE，此時車輛仍在車道中間
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT2_Fall; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正：REV 應在車輛抵達 A 感測器時才結束，並比照 FWD 增加 10 秒駐留緩衝狀態 REV_HOLD（新增常數，值 6）。
修正 REV 且 A 上升緣 \(\to\) REV_HOLD
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT1_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) REV_HOLD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 駐留計時：HOLD 與 REV_HOLD 共用 10 秒計時器 TON_1
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=HOLD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_1; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#10s; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0); (0.45,0) – (0.45,-1.1); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=REV_HOLD; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (3.35,-1.1) – (3.35,0);
修正 REV_HOLD 計時到 \(\to\) IDLE（狀態限定，見問題 4）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV_HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=TON_1.Q; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
問題 4：計時器 Done 位元未限定狀態
現況 原 Rung 12／14：TON.Q 一成立就無條件寫 IDLE，可能覆寫 FAULT 等狀態
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=TON_1.Q; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 每一條寫入 STATE 的 rung，第一個條件一律是「目前狀態」
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=TON_1.Q; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
原 Rung 12（TON_3.Q 逾時）除了加狀態限定外，目的地也應由 IDLE 改為 FAULT，見問題 6 的階梯圖。
問題 5：邊緣偵測標籤不一致
現況 原 Rung 1：接點讀 INPUT1_Last，但 Rung 3 線圈寫的是 M_INPUT1_Last —— 若為兩個變數，邊緣偵測全失效
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=INPUT1; (1.68,0) – (2.92,0); at (3.3,0) cnc=; at (3.3,0.24) INPUT1_Last; (3.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Rise; (13.28,0) – (13.6,0);
修正後三條 rung 全部使用同一個變數 M_INPUT1_Last， 且 _Last 的更新 rung 必須排在最後（INPUT2 比照辦理）：
修正 上升緣：本週期為 1、上週期為 0
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=INPUT1; (1.68,0) – (2.92,0); at (3.3,0) cnc=M_INPUT1_Last; (3.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Rise; (13.28,0) – (13.6,0);
修正 下降緣：本週期為 0、上週期為 1
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cnc=INPUT1; (1.68,0) – (2.92,0); at (3.3,0) cno=M_INPUT1_Last; (3.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Fall; (13.28,0) – (13.6,0);
修正 上週期值更新 —— 必須放在所有使用 _Last 的 rung 之後
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=INPUT1; (1.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Last; (13.28,0) – (13.6,0);
更好的做法是直接改用平台內建的上升緣接點（見建議 12 與第 5 節 R1、R2）， 六條 rung 縮為兩條，並徹底消除此類命名錯誤。
重要問題修正階梯圖（問題 6–11）
問題 6：60 秒逾時應轉入 FAULT，而非回 IDLE
車輛拋錨卡在車道內超過 60 秒屬於異常；回 IDLE 會放行對向車輛。 修正：FWD 與 REV 共用通行逾時計時器，逾時即閂鎖故障並轉入 FAULT （占用燈由輸出 rung 在 FAULT 狀態下保持點亮，見問題 7）。
修正 通行逾時計時：FWD 或 REV 期間累計 60 秒
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=FWD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_3; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#60s; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0); (0.45,0) – (0.45,-1.1); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=REV; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (3.35,-1.1) – (3.35,0);
修正 逾時 \(\to\) 進入 FAULT 並閂鎖，需人員確認車道淨空後復歸
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cno=TON_3.Q; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FAULT \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0); (10.5,0) – (10.5,-1.1); (10.5,-1.1) – (12.52,-1.1); at (12.9,-1.1) scoil=FaultLatch; (13.28,-1.1) – (13.6,-1.1);
問題 7：REV 狀態不驅動占用指示
原 Rung 17 只有 FWD／HOLD 點亮 OUTPUT_1。 修正：REV、REV_HOLD 也並聯進來；FAULT 期間同樣保持點亮 （車道狀況未知，必須封鎖）。
修正 占用燈 = 狀態的純函數，五個狀態並聯
(0,0.85) – (0,-4.9); (13.6,0.85) – (13.6,-4.9); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=FWD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (12.52,0); at (12.9,0) coil=OUTPUT_1; (13.28,0) – (13.6,0); (0.45,0) – (0.45,-4.4); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=HOLD; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (0.45,-2.2) – (0.67,-2.2); (1.9-1.05,-2.2-0.4) rectangle (1.9+1.05,-2.2+0.4); at (1.9,-2.2+0.21) EQU; at (1.9,-2.2-0.15) STATE=REV; (1.9-1.23,-2.2) – (1.9-1.05,-2.2); (1.9+1.05,-2.2) – (1.9+1.23,-2.2);
(3.13,-2.2) – (3.35,-2.2); (0.45,-3.3) – (0.67,-3.3); (1.9-1.05,-3.3-0.4) rectangle (1.9+1.05,-3.3+0.4); at (1.9,-3.3+0.21) EQU; at (1.9,-3.3-0.15) STATE=REV_HOLD; (1.9-1.23,-3.3) – (1.9-1.05,-3.3); (1.9+1.05,-3.3) – (1.9+1.23,-3.3);
(3.13,-3.3) – (3.35,-3.3); (0.45,-4.4) – (0.67,-4.4); (1.9-1.05,-4.4-0.4) rectangle (1.9+1.05,-4.4+0.4); at (1.9,-4.4+0.21) EQU; at (1.9,-4.4-0.15) STATE=FAULT; (1.9-1.23,-4.4) – (1.9-1.05,-4.4); (1.9+1.05,-4.4) – (1.9+1.23,-4.4);
(3.13,-4.4) – (3.35,-4.4); (3.35,-4.4) – (3.35,0);
問題 8：兩端同時來車 \(\to\) 雙方永久等待
原程式以「上升緣 + 對側淨空」觸發，兩端幾乎同時遮斷時兩條 rung 都不成立， 且邊緣旗標一個週期後消失，永遠卡死。修正：進入條件改用電平 （車輛持續遮斷感測器即成立），並新增「兩側同時佔用」的固定優先權裁決 rung。
修正 IDLE \(\to\) FWD：A 遮斷（電平）且 B 淨空
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FWD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 IDLE \(\to\) REV：B 遮斷（電平）且 A 淨空
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT2; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT1; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) REV \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 同時佔用的仲裁：固定 A 側優先（依現場規則亦可改為進入 FAULT 或輪流優先）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cno=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FWD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
注意 rung 排列順序：兩條單側 rung 在前、仲裁 rung 在後；三條的條件互斥， 同一週期至多一條成立。
問題 9：兩支感測器共用一顆卡住偵測計時器
現況 原 Rung 19：INPUT1 OR INPUT2 餵同一顆 TON，計時跨感測器連續累積而誤報
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cno=INPUT1; (1.68,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_2; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#5m; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0); (0.45,0) – (0.45,-1.0); (0.45,-1.0) – (0.92,-1.0); at (1.3,-1.0) cno=INPUT2; (1.68,-1.0) – (2.15,-1.0); (2.15,-1.0) – (2.15,0);
修正：每支感測器各用一顆計時器，且僅在與狀態矛盾時計時 （IDLE 卻長時間遮斷才可疑；通行中的合法遮斷不計）。
修正 A 端獨立卡住偵測
(0,0.85) – (0,-0.8); (13.6,0.85) – (13.6,-0.8); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_2A; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#5m; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0);
修正 B 端獨立卡住偵測
(0,0.85) – (0,-0.8); (13.6,0.85) – (13.6,-0.8); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT2; (4.08,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_2B; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#5m; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0);
修正 任一計時到即判定感測器卡住
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cno=TON_2A.Q; (1.68,0) – (12.52,0); at (12.9,0) coil=SensorStuck; (13.28,0) – (13.6,0); (0.45,0) – (0.45,-1.0); (0.45,-1.0) – (0.92,-1.0); at (1.3,-1.0) cno=TON_2B.Q; (1.68,-1.0) – (2.15,-1.0); (2.15,-1.0) – (2.15,0);
問題 10：故障優先權與復歸順序耦合
修正有兩點：(1) 「FaultLatch \(\to\) FAULT」rung 移到狀態機之前， 故障成立的同一週期即接管狀態；(2) 解閂與回 IDLE 合併為單一 rung， 不再依賴三條 rung 的掃描順序。
修正 故障接管 —— 置於所有狀態轉移 rung 之前
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=FaultLatch; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FAULT \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 復歸整合：解閂與回 IDLE 同一 rung 完成
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cpe=PB_RESET; (1.68,0) – (1.97,0); (3.2-1.05,0-0.4) rectangle (3.2+1.05,0+0.4); at (3.2,0+0.21) EQU; at (3.2,0-0.15) STATE=FAULT; (3.2-1.23,0) – (3.2-1.05,0); (3.2+1.05,0) – (3.2+1.23,0);
(4.43,0) – (5.02,0); at (5.4,0) cnc=SensorStuck; (5.78,0) – (12.52,0); at (12.9,0) ucoil=FaultLatch; (13.28,0) – (13.6,0); (10.5,0) – (10.5,-1.1); (10.5,-1.1) – (10.77,-1.1); (12.1-1.15,-1.1-0.45) rectangle (12.1+1.15,-1.1+0.45); at (12.1,-1.1+0.24) MOV; at (12.1,-1.1-0.15) IDLE \(\to\) STATE; (12.1-1.33,-1.1) – (12.1-1.15,-1.1); (12.1+1.15,-1.1) – (12.1+1.33,-1.1);
(13.43,-1.1) – (13.6,-1.1);
問題 11：多車跟進 —— 車輛計數（選配）
若場域允許多車同時在車道內，以「車道內車輛數」取代純計時判斷， 以下以 FWD 方向為例（REV 鏡像對稱）：
修正 A 端進入一台，計數 \(+1\)（邊緣觸發，避免每週期累加）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=FWD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT1_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) ADD; at (12.1,0-0.15) VehCnt+1 \(\to\) VehCnt; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 B 端離開一台，計數 \(-1\)
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=FWD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT2_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) SUB; at (12.1,0-0.15) VehCnt-1 \(\to\) VehCnt; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
修正 回 IDLE 的條件加上「車道內車輛數 = 0」
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=TON_1.Q; (4.08,0) – (4.77,0); (6.0-1.05,0-0.4) rectangle (6.0+1.05,0+0.4); at (6.0,0+0.21) EQU; at (6.0,0-0.15) VehCnt=0; (6.0-1.23,0) – (6.0-1.05,0); (6.0+1.05,0) – (6.0+1.23,0);
(7.23,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
車輛計數屬功能擴充，第 5 節的完整程式未納入；導入時另需處理 VehCnt 的下限保護與 FWD 期間後車跟進重啟逾時計時等細節。
可維護性建議階梯圖（建議 12–15）
建議 12：改用內建邊緣接點
手寫三段式邊緣偵測（6 條 rung、2 個中間變數）以內建上升緣接點（OSR／R_TRIG） 取代，每支感測器一條 rung 即可，並徹底避免問題 5 的命名斷裂：
修正 一條 rung 取代原 Rung 1–3
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cpe=INPUT1; (1.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Rise; (13.28,0) – (13.6,0);
建議 13：狀態機集中化
梯形圖版本的落地原則（完整落實見第 5 節）：
每個
MOV\(\to\)STATE一律先串EQU(STATE, 現態)；相同現態的多個轉移條件彼此互斥；
故障接管 rung 放在所有轉移之前、輸出 rung 放在最後。
若平台支援，狀態轉移改用 ST 的 CASE 集中管理更佳（見審查報告第 3.2 節）。
建議 14：計時器與變數命名語義化
| 原名 | 建議名 | 原名 | 建議名 |
|---|---|---|---|
TON_1 |
tHoldDwell（10 s） |
OUTPUT_1 |
LaneOccupiedLamp |
TON_2A/2B |
tStuckA／tStuckB（5 min） |
OUTPUT_2 |
FaultLamp |
TON_3 |
tTransitTimeout（60 s） |
INPUT1/2 |
SensorA／SensorB |
修正 命名語義化後的同一條 rung，用途一目瞭然
(0,0.85) – (0,-0.8); (13.6,0.85) – (13.6,-0.8); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=FWD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) tTransitTimeout; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#60s; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0);
建議 15：手動按鈕一律取上升緣
已落實於問題 2／問題 10 的復歸 rung（PB_RESET 使用 P 接點）： 按住不放只觸發一次，不會每個掃描週期重複執行 MOV。
修正後完整程式（Rung 1–23）
以下為整合所有修正後的完整梯形圖程式。結構依「輸入處理 \(\to\) 故障偵測 \(\to\) 狀態轉移 \(\to\) 計時 \(\to\) 復歸 \(\to\) 輸出」排列，STATE 的每個寫入點 都以現態為第一條件，輸出為狀態的純函數。
輸入處理與初始化（R1–R3）
R1 INPUT1 上升緣（內建邊緣接點，取代原 Rung 1–3）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cpe=INPUT1; (1.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT1_Rise; (13.28,0) – (13.6,0);
R2 INPUT2 上升緣（取代原 Rung 4–6）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cpe=INPUT2; (1.68,0) – (12.52,0); at (12.9,0) coil=M_INPUT2_Rise; (13.28,0) – (13.6,0);
R3 初始化：INIT 且車道淨空 \(\to\) IDLE（修正問題 1）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=INIT; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cnc=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
故障偵測與接管（R4–R8）
R4 A 端卡住偵測：IDLE 卻持續遮斷 5 分鐘（修正問題 9）
(0,0.85) – (0,-0.8); (13.6,0.85) – (13.6,-0.8); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_2A; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#5m; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0);
R5 B 端卡住偵測
(0,0.85) – (0,-0.8); (13.6,0.85) – (13.6,-0.8); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT2; (4.08,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_2B; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#5m; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0);
R6 任一計時到 \(\to\) SensorStuck
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cno=TON_2A.Q; (1.68,0) – (12.52,0); at (12.9,0) coil=SensorStuck; (13.28,0) – (13.6,0); (0.45,0) – (0.45,-1.0); (0.45,-1.0) – (0.92,-1.0); at (1.3,-1.0) cno=TON_2B.Q; (1.68,-1.0) – (2.15,-1.0); (2.15,-1.0) – (2.15,0);
R7 卡住即閂鎖故障
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=SensorStuck; (1.68,0) – (12.52,0); at (12.9,0) scoil=FaultLatch; (13.28,0) – (13.6,0);
R8 故障接管 —— 置於狀態機之前（修正問題 10）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=FaultLatch; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FAULT \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
狀態轉移（R9–R13）
R9 IDLE \(\to\) FWD：A 遮斷（電平）且 B 淨空（修正問題 8）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FWD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R10 IDLE \(\to\) REV：B 遮斷（電平）且 A 淨空
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT2; (4.08,0) – (5.22,0); at (5.6,0) cnc=INPUT1; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) REV \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R11 同時佔用仲裁：A 側優先（修正問題 8）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=IDLE; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=INPUT1; (4.08,0) – (5.22,0); at (5.6,0) cno=INPUT2; (5.98,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FWD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R12 FWD \(\to\) HOLD：車輛通過 B
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=FWD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT2_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) HOLD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R13 REV \(\to\) REV_HOLD：車輛抵達 A（修正問題 3）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT1_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) REV_HOLD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
計時與逾時（R14–R20）
R14 通行逾時計時：FWD 或 REV 共用 60 秒（修正問題 6、7 之計時部分）
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=FWD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_3; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#60s; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0); (0.45,0) – (0.45,-1.1); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=REV; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (3.35,-1.1) – (3.35,0);
R15 逾時 \(\to\) FAULT 並閂鎖（修正問題 4、6）
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cno=TON_3.Q; (1.68,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FAULT \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0); (10.5,0) – (10.5,-1.1); (10.5,-1.1) – (12.52,-1.1); at (12.9,-1.1) scoil=FaultLatch; (13.28,-1.1) – (13.6,-1.1);
R16 駐留計時：HOLD 或 REV_HOLD 共用 10 秒
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=HOLD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (10.67,0); (11.9-1.05,0-0.62) rectangle (11.9+1.05,0+0.62); at (11.9,0+0.4) TON_1; at (11.9-0.82,0+0.16) IN; at (11.9+0.84,0+0.16) Q; at (11.9,0-0.36) PT: T#10s; (11.9-1.23,0) – (11.9-1.05,0); (11.9+1.05,0) – (11.9+1.23,0);
(13.13,0) – (13.6,0); (0.45,0) – (0.45,-1.1); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=REV_HOLD; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (3.35,-1.1) – (3.35,0);
R17 HOLD 駐留期滿 \(\to\) IDLE（狀態限定，修正問題 4）
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=TON_1.Q; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R18 REV_HOLD 駐留期滿 \(\to\) IDLE
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV_HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=TON_1.Q; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) IDLE \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R19 HOLD 期間後車自 A 跟進 \(\to\) 回 FWD
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT1_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) FWD \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
R20 REV_HOLD 期間後車自 B 跟進 \(\to\) 回 REV
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.27,0); (1.5-1.05,0-0.4) rectangle (1.5+1.05,0+0.4); at (1.5,0+0.21) EQU; at (1.5,0-0.15) STATE=REV_HOLD; (1.5-1.23,0) – (1.5-1.05,0); (1.5+1.05,0) – (1.5+1.23,0);
(2.73,0) – (3.32,0); at (3.7,0) cno=M_INPUT2_Rise; (4.08,0) – (10.77,0); (12.1-1.15,0-0.45) rectangle (12.1+1.15,0+0.45); at (12.1,0+0.24) MOV; at (12.1,0-0.15) REV \(\to\) STATE; (12.1-1.33,0) – (12.1-1.15,0); (12.1+1.15,0) – (12.1+1.33,0);
(13.43,0) – (13.6,0);
故障復歸與輸出（R21–R23）
R21 復歸：按鈕上升緣、限 FAULT 狀態、故障已排除；解閂與回 IDLE 一次完成（修正問題 2、10、建議 15）
(0,0.85) – (0,-1.7); (13.6,0.85) – (13.6,-1.7); (0,0) – (0.92,0); at (1.3,0) cpe=PB_RESET; (1.68,0) – (1.97,0); (3.2-1.05,0-0.4) rectangle (3.2+1.05,0+0.4); at (3.2,0+0.21) EQU; at (3.2,0-0.15) STATE=FAULT; (3.2-1.23,0) – (3.2-1.05,0); (3.2+1.05,0) – (3.2+1.23,0);
(4.43,0) – (5.02,0); at (5.4,0) cnc=SensorStuck; (5.78,0) – (12.52,0); at (12.9,0) ucoil=FaultLatch; (13.28,0) – (13.6,0); (10.5,0) – (10.5,-1.1); (10.5,-1.1) – (10.77,-1.1); (12.1-1.15,-1.1-0.45) rectangle (12.1+1.15,-1.1+0.45); at (12.1,-1.1+0.24) MOV; at (12.1,-1.1-0.15) IDLE \(\to\) STATE; (12.1-1.33,-1.1) – (12.1-1.15,-1.1); (12.1+1.15,-1.1) – (12.1+1.33,-1.1);
(13.43,-1.1) – (13.6,-1.1);
R22 占用燈：通行、駐留與故障期間皆點亮（修正問題 7）
(0,0.85) – (0,-4.9); (13.6,0.85) – (13.6,-4.9); (0,0) – (0.67,0); (1.9-1.05,0-0.4) rectangle (1.9+1.05,0+0.4); at (1.9,0+0.21) EQU; at (1.9,0-0.15) STATE=FWD; (1.9-1.23,0) – (1.9-1.05,0); (1.9+1.05,0) – (1.9+1.23,0);
(3.13,0) – (12.52,0); at (12.9,0) coil=OUTPUT_1; (13.28,0) – (13.6,0); (0.45,0) – (0.45,-4.4); (0.45,-1.1) – (0.67,-1.1); (1.9-1.05,-1.1-0.4) rectangle (1.9+1.05,-1.1+0.4); at (1.9,-1.1+0.21) EQU; at (1.9,-1.1-0.15) STATE=HOLD; (1.9-1.23,-1.1) – (1.9-1.05,-1.1); (1.9+1.05,-1.1) – (1.9+1.23,-1.1);
(3.13,-1.1) – (3.35,-1.1); (0.45,-2.2) – (0.67,-2.2); (1.9-1.05,-2.2-0.4) rectangle (1.9+1.05,-2.2+0.4); at (1.9,-2.2+0.21) EQU; at (1.9,-2.2-0.15) STATE=REV; (1.9-1.23,-2.2) – (1.9-1.05,-2.2); (1.9+1.05,-2.2) – (1.9+1.23,-2.2);
(3.13,-2.2) – (3.35,-2.2); (0.45,-3.3) – (0.67,-3.3); (1.9-1.05,-3.3-0.4) rectangle (1.9+1.05,-3.3+0.4); at (1.9,-3.3+0.21) EQU; at (1.9,-3.3-0.15) STATE=REV_HOLD; (1.9-1.23,-3.3) – (1.9-1.05,-3.3); (1.9+1.05,-3.3) – (1.9+1.23,-3.3);
(3.13,-3.3) – (3.35,-3.3); (0.45,-4.4) – (0.67,-4.4); (1.9-1.05,-4.4-0.4) rectangle (1.9+1.05,-4.4+0.4); at (1.9,-4.4+0.21) EQU; at (1.9,-4.4-0.15) STATE=FAULT; (1.9-1.23,-4.4) – (1.9-1.05,-4.4); (1.9+1.05,-4.4) – (1.9+1.23,-4.4);
(3.13,-4.4) – (3.35,-4.4); (3.35,-4.4) – (3.35,0);
R23 故障燈
(0,0.85) – (0,-0.55); (13.6,0.85) – (13.6,-0.55); (0,0) – (0.92,0); at (1.3,0) cno=FaultLatch; (1.68,0) – (12.52,0); at (12.9,0) coil=OUTPUT_2; (13.28,0) – (13.6,0);
設計要點備忘
寫入點限定：
STATE的寫入 rung（R3、R8–R13、R15、R17–R21） 除故障接管（R8）與逾時（R15，由狀態驅動的計時器保證）外， 全部以EQU(STATE, 現態)為第一條件，同一現態的轉移條件互斥。掃描順序：邊緣旗標（R1–R2）最先產生；故障接管（R8）在所有轉移之前； 輸出（R22–R23）在最後，為狀態的純函數。
計時器：全部使用 TON（非保持型），IN 由狀態驅動，離開狀態即自動復歸； R15、R17、R18 使用
TON.Q時皆有狀態限定，即使日後搬動 rung 也不會誤寫。逾時即故障：60 秒逾時不再放行對向車輛，一律閂鎖
FAULT， 由人員確認車道淨空後以 R21 復歸。選配：多車場域請加入第 3.6 節的車輛計數， 以「車數 = 0」取代純計時作為回
IDLE的條件。