diff --git a/paradox/hardware/panel.py b/paradox/hardware/panel.py
index 4298bf10..0f3ab558 100644
--- a/paradox/hardware/panel.py
+++ b/paradox/hardware/panel.py
@@ -100,7 +100,13 @@ def get_error_message(error_code) -> str:
         elif error_code == 0x1C:
             message = "Invalid label number"
         else:
-            message = error_str
+            # Include the hex form so unknown codes can be looked up easily
+            # in Paradox docs / issues (e.g. "29 (0x1D)" reported by panels
+            # in response to PGM and panic commands on some EVO firmwares).
+            if isinstance(error_code, int):
+                message = f"{error_str} (0x{error_code:02X})"
+            else:
+                message = error_str
 
         return message
 
diff --git a/tests/hardware/evo/test_pgm.py b/tests/hardware/evo/test_pgm.py
index 88687bcd..70491868 100644
--- a/tests/hardware/evo/test_pgm.py
+++ b/tests/hardware/evo/test_pgm.py
@@ -68,6 +68,19 @@ def test_pgm4_deactivate_and_monitor():
     assert a == expected_out
 
 
+def test_pgm5_activate_and_monitor():
+    # PGM 5 maps to bit 4 of the bitmap (byte offset 6 = 0x10).
+    # Onboard PGM 5 is the only dry relay on the EVO192 mainboard; see
+    # https://github.com/ParadoxAlarmInterface/pai/issues/580
+    expected_out = unhexlify("4013060000001000000000000000030000006c")
+
+    pgms = [5]
+
+    a = PerformPGMAction.build({"fields": {"value": {"pgms": pgms, "command": "on"}}})
+
+    assert a == expected_out
+
+
 def test_pgm_flags_1():
     parser = PGMFlags(1)
     assert parser.sizeof() == 4