Add methods to read and write errors and diagnostics

schunk_egu_egk_gripper_dummy/config/data.json

@@ -1,6 +1,6 @@
 {
     "0x0040": [
-        "800000800000A25800000000000000EF"
+        "800000800000A25800000000D90000EF"
     ],
     "0x0048": [
         "05000000000000000000000000000000"

schunk_egu_egk_gripper_dummy/src/dummy.py

@@ -15,6 +15,8 @@ def __init__(self):
         self.data = None
         self.plc_input = "0x0040"
         self.plc_output = "0x0048"
+        self.error_byte = 12
+        self.diagnostics_byte = 15
         self.reserved_status_bits = [10, 15] + list(range(18, 31))
 
         enum_config = os.path.join(
@@ -122,3 +124,25 @@ def get_status_bit(self, bit: int) -> int | bool:
             return False
         byte_index, bit_index = divmod(bit, 8)
         return 1 if self.plc_input_buffer[byte_index] & (1 << bit_index) != 0 else 0
+
+    def set_status_error(self, error: str) -> bool:
+        try:
+            self.plc_input_buffer[self.error_byte] = int(error, 16)
+            return True
+        except ValueError:
+            return False
+
+    def get_status_error(self) -> str:
+        return hex(self.plc_input_buffer[self.error_byte]).replace("0x", "").upper()
+
+    def set_status_diagnostics(self, diagnostics: str) -> bool:
+        try:
+            self.plc_input_buffer[self.diagnostics_byte] = int(diagnostics, 16)
+            return True
+        except ValueError:
+            return False
+
+    def get_status_diagnostics(self) -> str:
+        return (
+            hex(self.plc_input_buffer[self.diagnostics_byte]).replace("0x", "").upper()
+        )

schunk_egu_egk_gripper_dummy/tests/test_plc_communication.py

@@ -52,17 +52,46 @@ def test_dummy_only_touches_specified_bits():
     assert dummy.get_plc_input() == before
 
 
+def test_dummy_supports_reading_and_writing_status_error():
+    dummy = Dummy()
+    error_codes = ["AA", "bb", "0xcc"]
+    expected = ["AA", "BB", "CC"]
+    for error, expected in zip(error_codes, expected):
+        dummy.set_status_error(error)
+        assert dummy.get_status_error() == expected
+
+
+def test_dummy_rejects_writing_invalid_status_error():
+    dummy = Dummy()
+    invalid_codes = ["zz", "-1", "aaa"]
+    for error in invalid_codes:
+        assert not dummy.set_status_error(error)
+
+
+def test_dummy_supports_reading_and_writing_status_diagnostics():
+    dummy = Dummy()
+    diagnostics_code = "EF"
+    dummy.set_status_diagnostics(diagnostics_code)
+    assert dummy.get_status_diagnostics() == diagnostics_code
+
+
+def test_dummy_rejects_writing_invalid_status_diagnostics():
+    dummy = Dummy()
+    invalid_codes = ["zz", "-1", "aaa"]
+    for code in invalid_codes:
+        assert not dummy.set_status_diagnostics(code)
+
+
 # See p. 24 in
 # Booting and establishing operational readiness [1]
 
 
-@pytest.mark.skip()
 def test_dummy_starts_in_error_state():
     dummy = Dummy()
-    query = {"inst": dummy.plc_input, "count": 1}
-    data = dummy.get_data(query)[0]
-    assert data[0:2] == "80"
-    assert data[30:] == "D9"  # ERR_FAST_STOP
+    assert dummy.get_status_bit(0) == 0  # not ready for operation
+    assert dummy.get_status_bit(7) == 1  # there's an error
+    assert dummy.get_status_error() == "D9"  # ERR_FAST_STOP
+    assert dummy.get_status_diagnostics() == "EF"  # ERR_COMM_LOST
 
 
 @pytest.mark.skip()