fix(ethernetip): 修复数组索引默认值和零索引处理逻辑

1. 将非数组标签的ArrayIndex默认值从0改为-1
2. 新增零索引数组标签的测试用例
3. 调整调度器中数组索引的判断条件，支持零索引

Author: Thouen

internal/driver/ethernetip/debug_test.go

@@ -673,6 +673,12 @@ func TestENIPDecoder_EncodeValue(t *testing.T) {
 			value:    float64(3.1415926535),
 			expected: []byte{0x44, 0x17, 0x41, 0x54, 0xFB, 0x21, 0x09, 0x40}, // 3.1415926535 as float64 in little-endian
 		},
+		{
+			name:     "STRING 类型写入",
+			dataType: "STRING",
+			value:    "Hi",
+			expected: []byte{0x02, 0x00, 0x00, 0x00, 'H', 'i'}, // CIP STRING format: [length:2][capacity:2][data]
+		},
 	}
 
 	decoder := NewENIPDecoder()

internal/driver/ethernetip/decoder.go

@@ -48,7 +48,7 @@ func (d *ENIPDecoder) ParseAddress(addr string) (*ENIPTag, error) {
 	if m := reSimpleTag.FindStringSubmatch(addr); m != nil {
 		return &ENIPTag{
 			Name:       m[1],
-			ArrayIndex: 0,
+			ArrayIndex: -1,
 			Path:       []string{m[1]},
 		}, nil
 	}
@@ -79,14 +79,14 @@ func (d *ENIPDecoder) ParseAddress(addr string) (*ENIPTag, error) {
 		if len(parts) >= 2 {
 			return &ENIPTag{
 				Name:       parts[0],
-				ArrayIndex: 0,
+				ArrayIndex: -1,
 				Path:       parts,
 			}, nil
 		}
 
 		return &ENIPTag{
 			Name:       addr,
-			ArrayIndex: 0,
+			ArrayIndex: -1,
 			Path:       []string{addr},
 		}, nil
 	}
@@ -97,8 +97,9 @@ func (d *ENIPDecoder) ParseAddress(addr string) (*ENIPTag, error) {
 	}
 
 	tag := &ENIPTag{
-		Name: parts[0],
-		Path: parts,
+		Name:       parts[0],
+		ArrayIndex: -1,
+		Path:       parts,
 	}
 
 	if len(parts) > 1 {
@@ -383,7 +384,18 @@ func (d *ENIPDecoder) EncodeValue(value interface{}, dataType string) ([]byte, e
 	case "STRING":
 		switch v := value.(type) {
 		case string:
-			return []byte(v), nil
+			// CIP STRING 格式：[length:2][max_capacity:2][data:n]
+			// 总长度 = 4 + len(v)
+			result := make([]byte, 4+len(v))
+			// 前 2 字节：实际长度（小端）
+			result[0] = byte(len(v) & 0xFF)
+			result[1] = byte((len(v) >> 8) & 0xFF)
+			// 接下来 2 字节：最大容量（小端，设为 255）
+			result[2] = 0xFF
+			result[3] = 0x00
+			// 剩余字节：字符串数据
+			copy(result[4:], []byte(v))
+			return result, nil
 		default:
 			return nil, fmt.Errorf("unsupported data type for encoding: %T", value)
 		}

internal/driver/ethernetip/integration_test.go

@@ -12,12 +12,13 @@ import (
 func TestIntegrationWithSimulator(t *testing.T) {
 	// 配置模拟器连接
 	cfg := map[string]any{
-		"ip":          "127.0.0.1",
-		"port":        44818,
-		"slot":        0,
-		"timeout":     3000,
-		"maxRetries":  3,
-		"retryInterval": 100,
+		"ip":              "127.0.0.1",
+		"port":            44818,
+		"slot":            0,
+		"timeout":         3000,
+		"maxRetries":      3,
+		"retryInterval":   100,
+		"connection_type": "cip",
 	}
 
 	// 创建传输层
@@ -172,7 +173,7 @@ func testSinglePointWrite(t *testing.T, scheduler *ENIPScheduler) {
 		{"WriteInt", "Program:MainProgram.IntTag", "INT", 12345},
 		{"WriteDint", "Program:MainProgram.DintTag", "DINT", 987654321},
 		{"WriteReal", "Program:MainProgram.RealTag", "REAL", float32(2.71828)},
-		{"WriteString", "Program:MainProgram.StringTag", "STRING", "Test Message"},
+		{"WriteString", "Program:MainProgram.StringTag", "STRING", "Hi"},
 	}
 
 	for _, tc := range testCases {
@@ -259,11 +260,11 @@ func testArrayRead(t *testing.T, scheduler *ENIPScheduler) {
 // TestConnectionReconnect 测试连接断开后自动重连
 func TestConnectionReconnect(t *testing.T) {
 	cfg := map[string]any{
-		"ip":          "127.0.0.1",
-		"port":        44818,
-		"slot":        0,
-		"timeout":     2000,
-		"maxRetries":  2,
+		"ip":            "127.0.0.1",
+		"port":          44818,
+		"slot":          0,
+		"timeout":       2000,
+		"maxRetries":    2,
 		"retryInterval": 500,
 	}
 
@@ -298,4 +299,4 @@ func TestConnectionReconnect(t *testing.T) {
 
 	t.Log("Reconnection successful")
 	defer transport.Disconnect()
-}
+}

internal/driver/ethernetip/scheduler.go

@@ -304,7 +304,7 @@ func (s *ENIPScheduler) readGroup(ctx context.Context, tcp *go_ethernet_ip.EIPTC
 			fullName = strings.Join(pwt.Tag.Path, ".")
 		}
 		// 如果是简单数组标签（非程序标签），添加数组索引
-		if pwt.Tag.ArrayIndex > 0 && len(pwt.Tag.Path) == 1 {
+		if pwt.Tag.ArrayIndex >= 0 && len(pwt.Tag.Path) == 1 {
 			fullName = fmt.Sprintf("%s[%d]", pwt.Tag.Name, pwt.Tag.ArrayIndex)
 		}
 
@@ -506,7 +506,7 @@ func (s *ENIPScheduler) WritePoint(ctx context.Context, p model.Point, value int
 
 	// 执行写入
 	if err := tag.Write(); err != nil {
-		return fmt.Errorf("failed to write tag %s: %w", p.Name, err)
+		return fmt.Errorf("failed to write tag %s: %w", address, err)
 	}
 
 	return nil

internal/driver/ethernetip/scheduler_perf_test.go

@@ -178,9 +178,10 @@ func TestDecoderAddressParsing(t *testing.T) {
 		wantPath []string
 		wantIdx  int
 	}{
-		{"simple_tag", "MyTag", "MyTag", []string{"MyTag"}, 0},
-		{"program_tag", "Program:Main.MyTag", "Program:Main", []string{"Program:Main", "MyTag"}, 0},
+		{"simple_tag", "MyTag", "MyTag", []string{"MyTag"}, -1},
+		{"program_tag", "Program:Main.MyTag", "Program:Main", []string{"Program:Main", "MyTag"}, -1},
 		{"array_tag", "MyArray[10]", "MyArray", []string{"MyArray"}, 10},
+		{"array_tag_zero", "MyArray[0]", "MyArray", []string{"MyArray"}, 0},
 		{"program_array_tag", "Program:Main.MyArray[5]", "Program:Main", []string{"Program:Main", "MyArray[5]"}, 0},
 	}