diff --git a/util/modbus/functions.go b/util/modbus/functions.go
index e3c212b69..bcb98e891 100644
--- a/util/modbus/functions.go
+++ b/util/modbus/functions.go
@@ -53,28 +53,37 @@ func decodeBool16(mask uint64) func(b []byte) float64 {
 	}
 }
 
-func decodeNaN16(nan uint16, f func(b []byte) float64) func(b []byte) float64 {
+func decodeNaN16(f func(b []byte) float64, nan ...uint16) func(b []byte) float64 {
 	return func(b []byte) float64 {
-		if binary.BigEndian.Uint16(b) == nan {
-			return 0
+		u := binary.BigEndian.Uint16(b)
+		for _, nan := range nan {
+			if u == nan {
+				return 0
+			}
 		}
 		return f(b)
 	}
 }
 
-func decodeNaN32(nan uint32, f func(b []byte) float64) func(b []byte) float64 {
+func decodeNaN32(f func(b []byte) float64, nan ...uint32) func(b []byte) float64 {
 	return func(b []byte) float64 {
-		if binary.BigEndian.Uint32(b) == nan {
-			return 0
+		u := binary.BigEndian.Uint32(b)
+		for _, nan := range nan {
+			if u == nan {
+				return 0
+			}
 		}
 		return f(b)
 	}
 }
 
-func decodeNaN64(nan uint64, f func(b []byte) float64) func(b []byte) float64 {
+func decodeNaN64(f func(b []byte) float64, nan ...uint64) func(b []byte) float64 {
 	return func(b []byte) float64 {
-		if binary.BigEndian.Uint64(b) == nan {
-			return 0
+		u := binary.BigEndian.Uint64(b)
+		for _, nan := range nan {
+			if u == nan {
+				return 0
+			}
 		}
 		return f(b)
 	}
diff --git a/util/modbus/modbus.go b/util/modbus/modbus.go
index b872c4f4c..c9e19b1c9 100644
--- a/util/modbus/modbus.go
+++ b/util/modbus/modbus.go
@@ -309,13 +309,13 @@ func RegisterOperation(r Register) (rs485.Operation, error) {
 		op.Transform = asFloat64(encoding.Int16)
 		op.ReadLen = 1
 	case "int16nan":
-		op.Transform = decodeNaN16(1<<15, asFloat64(encoding.Int16))
+		op.Transform = decodeNaN16(asFloat64(encoding.Int16), 1<<15, 1<<15-1)
 		op.ReadLen = 1
 	case "uint16":
 		op.Transform = asFloat64(encoding.Uint16)
 		op.ReadLen = 1
 	case "uint16nan":
-		op.Transform = decodeNaN16(0xFFFF, asFloat64(encoding.Uint16))
+		op.Transform = decodeNaN16(asFloat64(encoding.Uint16), 1<<16-1)
 		op.ReadLen = 1
 	case "bool16":
 		mask, err := decodeMask(r.BitMask)
@@ -329,7 +329,7 @@ func RegisterOperation(r Register) (rs485.Operation, error) {
 	case "int32":
 		op.Transform = asFloat64(encoding.Int32)
 	case "int32nan":
-		op.Transform = decodeNaN32(1<<31, asFloat64(encoding.Int32))
+		op.Transform = decodeNaN32(asFloat64(encoding.Int32), 1<<31, 1<<31-1)
 	case "int32s":
 		op.Transform = asFloat64(encoding.Int32LswFirst)
 	case "uint32":
@@ -337,7 +337,7 @@ func RegisterOperation(r Register) (rs485.Operation, error) {
 	case "uint32s":
 		op.Transform = asFloat64(encoding.Uint32LswFirst)
 	case "uint32nan":
-		op.Transform = decodeNaN32(0xFFFFFFFF, asFloat64(encoding.Uint32))
+		op.Transform = decodeNaN32(asFloat64(encoding.Uint32), 1<<32-1)
 	case "float32", "ieee754":
 		op.Transform = asFloat64(encoding.Float32)
 	case "float32s", "ieee754s":
@@ -348,7 +348,7 @@ func RegisterOperation(r Register) (rs485.Operation, error) {
 		op.Transform = asFloat64(encoding.Uint64)
 		op.ReadLen = 4
 	case "uint64nan":
-		op.Transform = decodeNaN64(0xFFFFFFFFFFFFFFFF, asFloat64(encoding.Uint64))
+		op.Transform = decodeNaN64(asFloat64(encoding.Uint64), 1<<64-1)
 		op.ReadLen = 4
 	case "float64":
 		op.Transform = encoding.Float64