reading out registers corrected

test_meter.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+from pymodbus.client import ModbusTcpClient
+import struct, sys
+
+MODBUS_IP   = "192.168.1.112"
+MODBUS_PORT = 502
+UNIT_ID     = 1
+
+METER_START = 40240  # Startadresse Model 203-Felder
+
+def to_i16(u16):  # unsigned 16 → signed 16
+    return struct.unpack(">h", struct.pack(">H", u16))[0]
+
+def read_regs(client, addr, count):
+    rr = client.read_holding_registers(address=addr, count=count, slave=UNIT_ID)
+    if rr.isError():
+        return None
+    return rr.registers
+
+def read_meter_power(client):
+    base = METER_START
+    p  = read_regs(client, base + 16, 1)   # M_AC_Power
+    pa = read_regs(client, base + 17, 1)   # Phase A
+    pb = read_regs(client, base + 18, 1)   # Phase B
+    pc = read_regs(client, base + 19, 1)   # Phase C
+    sf = read_regs(client, base + 20, 1)   # Scale Factor
+    if not p or not sf:
+        return None
+    sff = to_i16(sf[0])
+    return {
+        "total": to_i16(p[0])  * (10 ** sff),
+        "A":     to_i16(pa[0]) * (10 ** sff) if pa else None,
+        "B":     to_i16(pb[0]) * (10 ** sff) if pb else None,
+        "C":     to_i16(pc[0]) * (10 ** sff) if pc else None,
+        "sf":    sff
+    }
+
+def fmt_w(v):
+    if v is None: return "-"
+    neg = v < 0
+    v = abs(v)
+    return f"{'-' if neg else ''}{v/1000:.2f} kW" if v >= 1000 else f"{'-' if neg else ''}{v:.0f} W"
+
+def main():
+    client = ModbusTcpClient(MODBUS_IP, port=MODBUS_PORT)
+    if not client.connect():
+        print("❌ Verbindung fehlgeschlagen."); sys.exit(1)
+    try:
+        m = read_meter_power(client)
+        if m:
+            print(f"Meter-Leistung: {fmt_w(m['total'])} "
+                  f"(A {fmt_w(m['A'])}, B {fmt_w(m['B'])}, C {fmt_w(m['C'])})  [SF={m['sf']}]")
+        else:
+            print("Meter-Leistung konnte nicht gelesen werden.")
+    finally:
+        client.close()
+
+if __name__ == "__main__":
+    main()