Pr turret

software/control/_def.py

@@ -1244,11 +1244,31 @@ def get_wellplate_settings(wellplate_format):
 OBJECTIVE_TURRET_BAUDRATE = 115200
 # Objective name -> turret slot index (1..4). Override per machine in .ini.
 OBJECTIVE_TURRET_POSITIONS = {"4x": 1, "10x": 2, "20x": 3, "40x": 4}
-# Global pulse offset added to every turret slot target, shifting the whole slot
-# frame relative to the homing switch (pulse 0). Corrects units whose limit switch
-# does not sit exactly at slot 1. 0 on all normal units; set per machine (may be
-# negative).
+# Pulse offset of slot 1 from the homing zero (the origin sensor's trigger edge);
+# the other slots follow at exactly 90-degree spacing. 0 on all normal units; set
+# per machine (may be negative). Software homing (2026-07) moved the zero slightly
+# vs the old driver homing — re-measure after upgrading a machine with an old value.
 OBJECTIVE_TURRET_OFFSET_PULSES = 0
+# Gear backlash compensation in turret degrees (0..1, 0 disables). When > 0 every
+# slot change first overshoots below the target by this angle and then approaches
+# it from below, so the final approach direction is always the same and gear
+# backlash cancels out.
+OBJECTIVE_TURRET_BACKLASH_DEG = 0.0
+# Set True for turret motor models wired with the opposite phase order (same
+# commands spin the other way). The controller then negates move targets, jog
+# signs and the homing-sweep direction bit, and flips position readbacks, so
+# slot mapping, offset and backlash logic keep working in the same logical
+# coordinate system — OBJECTIVE_TURRET_OFFSET_PULSES is always logical-coordinate
+# pulses. After toggling on an existing machine, re-home and re-measure the
+# offset: the physical zero moves with the sweep direction.
+OBJECTIVE_TURRET_DIRECTION_INVERTED = False
+# Set True for objective changers whose origin-switch sensor triggers on the
+# opposite logic level (port of SingleMotor's "原点开关极性取反" option, 2026-08-12).
+# Software homing / distance search then invert the DI1 trigger verdict, so the
+# homing direction and the sweep-backoff-fine-search state machine stay unchanged.
+# Toggling on an existing machine requires re-homing: the sensor edge found by
+# fine search (and thus the physical zero) sits on the other side of the window.
+OBJECTIVE_TURRET_DI_INVERT = False
 
 
 def _validate_objective_changer_flags(use_xeryon: bool, use_turret: bool) -> None:

software/control/microscope.py

@@ -158,6 +158,9 @@ def build_from_global_config(
                 baudrate=control._def.OBJECTIVE_TURRET_BAUDRATE,
                 positions=control._def.OBJECTIVE_TURRET_POSITIONS,
                 offset_pulses=control._def.OBJECTIVE_TURRET_OFFSET_PULSES,
+                backlash_deg=control._def.OBJECTIVE_TURRET_BACKLASH_DEG,
+                direction_inverted=control._def.OBJECTIVE_TURRET_DIRECTION_INVERTED,
+                di_invert=control._def.OBJECTIVE_TURRET_DI_INVERT,
                 stage=stage,
             )
             objective_changer = (

software/control/modbus_rtu.py

@@ -416,6 +416,19 @@ def read_input_register(self, slave_id: int, address: int) -> int:
         response = self._send_receive(frame, expected_response_len=7)
         return (response[3] << 8) | response[4]
 
+    def read_input_registers(self, slave_id: int, address: int, count: int) -> list[int]:
+        """Read `count` consecutive 16-bit input registers in one FC 0x04 transaction.
+
+        One frame instead of `count` round-trips — needed by pollers that must see a
+        consistent snapshot of several registers (e.g. DI level + position + alarm)
+        within a tight polling period.
+        """
+        self._require_connected()
+        frame = build_read_input_registers_frame(slave_id, address, count)
+        # Response: slave(1) + fc(1) + byte_count(1) + data(2*count) + crc(2)
+        response = self._send_receive(frame, expected_response_len=5 + 2 * count)
+        return [(response[3 + 2 * i] << 8) | response[4 + 2 * i] for i in range(count)]
+
     def read_input_register_32bit(self, slave_id: int, address: int, signed: bool = False) -> int:
         """Read a 32-bit input register pair via FC 0x04 (see read_input_register)."""
         self._require_connected()