diff --git a/client.go b/client.go
index 9599246..a22e2a5 100644
--- a/client.go
+++ b/client.go
@@ -1188,11 +1188,11 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
 		unitId: mc.unitId,
 	}
 
-	if functionCode != fcCustomize {
-		err = ErrUnexpectedParameters
-		mc.logger.Errorf("unexpected function code (%d)", functionCode)
-		return
-	}
+	// if functionCode != fcCustomize {
+	// 	err = ErrUnexpectedParameters
+	// 	mc.logger.Errorf("unexpected function code (%d)", functionCode)
+	// 	return
+	// }
 
 	if functionCode == 0 {
 		err = ErrUnexpectedParameters