Enphase: modbus interface (SunSpec 700) (#30121)

Co-authored-by: andig <andi@evcc.io>
Co-authored-by: andig <cpuidle@gmail.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

templates/definition/meter/enphase-modbus.yaml

@@ -0,0 +1,51 @@
+template: enphase-modbus
+products:
+  - brand: Enphase
+    description:
+      generic: IQ Gateway (Modbus)
+requirements:
+  description:
+    en: |
+      Requires Enphase support to enable modbus functionality on IQ Gateway.
+    de: |
+      Erfordert Enphase-Unterstützung, um die Modbus-Funktionalität auf dem IQ Gateway zu aktivieren.
+params:
+  - name: usage
+    choice: ["pv"]
+  - name: modbus
+    choice: ["tcpip"]
+    id: 1
+render: |
+  type: custom
+  # sunspec model 701 (DER AC Measurement)
+  {{- if eq .usage "pv" }}
+  power:
+    source: sunspec
+    {{- include "modbus" . | indent 2 }}
+    value: 701:W
+  energy:
+    source: sunspec
+    {{- include "modbus" . | indent 2 }}
+    value: 701:TotWhInj
+    scale: 0.001
+  currents:
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:AL1
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:AL2
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:AL3
+  voltages:
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:VL1
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:VL2
+    - source: sunspec
+      {{- include "modbus" . | indent 4 }}
+      value: 701:VL3
+  {{- end }}