diff --git a/src/modbus/config.rs b/src/modbus/config.rs
index f369b83..d7f8e80 100644
--- a/src/modbus/config.rs
+++ b/src/modbus/config.rs
@@ -1,4 +1,5 @@
 use serde::{Deserialize, Serialize};
+use serde_json::json;
 use std::time::Duration;
 
 #[derive(Clone, Serialize, Deserialize)]
@@ -202,3 +203,111 @@ struct Unit(crate::modbus::UnitId);
 fn default_address_offset() -> i8 {
     0
 }
+
+#[test]
+fn parse_minimal_tcp_connect_config() {
+    let result = serde_json::from_value::<Connect>(json!({
+        "host": "1.1.1.1"
+    }));
+    assert!(result.is_ok());
+
+    let connect = result.unwrap();
+    assert!(matches!(
+        connect.settings,
+        ModbusProto::Tcp {
+            ref host,
+            port: 502
+        } if host == "1.1.1.1"
+    ))
+}
+
+#[test]
+fn parse_full_tcp_connect_config() {
+    let result = serde_json::from_value::<Connect>(json!({
+        "host": "10.10.10.219",
+        "unit": 1,
+        "address_offset": -1,
+        "input": [
+            {
+                "address": 5017,
+                "type": "u32",
+                "name": "dc_power",
+                "swap_words": false,
+                "period": "3s"
+            },
+            {
+                "address": 5008,
+                "type": "s16",
+                "name": "internal_temperature",
+                "period": "1m"
+            },
+            {
+                "address": 13008,
+                "type": "s32",
+                "name": "load_power",
+                "swap_words": false,
+                "period": "3s"
+            },
+            {
+                "address": 13010,
+                "type": "s32",
+                "name": "export_power",
+                "swap_words": false,
+                "period": "3s"
+            },
+            {
+                "address": 13022,
+                "name": "battery_power",
+                "period": "3s"
+            },
+            {
+                "address": 13023,
+                "name": "battery_level",
+                "period": "1m"
+            },
+            {
+                "address": 13024,
+                "name": "battery_health",
+                "period": "10m"
+            }
+        ],
+        "hold": [
+            {
+                "address": 13058,
+                "name": "max_soc",
+                "period": "90s"
+            },
+            {
+                "address": 13059,
+                "name": "min_soc",
+                "period": "90s"
+            }
+        ]
+    }));
+
+    assert!(result.is_ok());
+}
+
+#[test]
+fn parse_minimal_rtu_connect_config() {
+    let result = serde_json::from_value::<Connect>(json!({
+        "tty": "/dev/ttyUSB0",
+        "baud_rate": 9600,
+    }));
+    assert!(result.is_ok());
+
+    let connect = result.unwrap();
+    use tokio_serial::*;
+    assert!(matches!(
+        connect.settings,
+        ModbusProto::Rtu {
+            ref tty,
+            baud_rate: 9600,
+            data_bits: DataBits::Eight,
+            stop_bits: StopBits::One,
+            flow_control: FlowControl::None,
+            parity: Parity::None,
+            ..
+        } if tty == "/dev/ttyUSB0"
+    ))
+}