feat: add IT6000C eload driver (PyVISA) with manual control CLI

drivers/eload.py

@@ -0,0 +1,97 @@
+import time
+
+import pyvisa
+
+
+class EloadError(Exception):
+    pass
+
+
+class EloadConnectionError(EloadError):
+    pass
+
+
+class EloadCommunicationError(EloadError):
+    pass
+
+
+class Eload:
+    """ITECH IT6000C bi-directional supply, used here as an electronic load (CV mode with +/- current limit)."""
+
+    def __init__(self, resource_name, baud_rate=9600, timeout_ms=3000, retries=3, retry_delay_s=0.2):
+        self._retries = retries
+        self._retry_delay_s = retry_delay_s
+        try:
+            self._rm = pyvisa.ResourceManager()
+            self._inst = self._rm.open_resource(resource_name)
+        except pyvisa.VisaIOError as exc:
+            raise EloadConnectionError(f"failed to open {resource_name}") from exc
+
+        self._inst.baud_rate = baud_rate
+        self._inst.write_termination = "\n"
+        self._inst.read_termination = "\n"
+        self._inst.timeout = timeout_ms
+
+    def _write(self, cmd):
+        for attempt in range(self._retries):
+            try:
+                self._inst.write(cmd)
+                return
+            except pyvisa.VisaIOError as exc:
+                if attempt == self._retries - 1:
+                    raise EloadCommunicationError(f"write failed: {cmd!r}") from exc
+                time.sleep(self._retry_delay_s)
+
+    def _query(self, cmd):
+        for attempt in range(self._retries):
+            try:
+                return self._inst.query(cmd).strip()
+            except pyvisa.VisaIOError as exc:
+                if attempt == self._retries - 1:
+                    raise EloadCommunicationError(f"query failed: {cmd!r}") from exc
+                time.sleep(self._retry_delay_s)
+
+    def set_remote(self):
+        self._write("SYST:REM")
+
+    def set_local(self):
+        self._write("SYST:LOC")
+
+    def set_mode_cv(self):
+        self._write("SOUR:FUNC VOLT")
+
+    def set_mode_cc(self):
+        self._write("SOUR:FUNC CURR")
+
+    def set_voltage(self, volts):
+        self._write(f"VOLT {volts}")
+
+    def set_current(self, amps):
+        self._write(f"CURR {amps}")
+
+    def set_current_limit_positive(self, amps):
+        self._write(f"CURR:LIM:POS {amps}")
+
+    def set_current_limit_negative(self, amps):
+        self._write(f"CURR:LIM:NEG {amps}")
+
+    def output_on(self):
+        self._write("OUTP ON")
+
+    def output_off(self):
+        self._write("OUTP OFF")
+
+    def is_output_on(self):
+        return self._query("OUTP?") == "1"
+
+    def measure_voltage(self):
+        return float(self._query("MEAS:VOLT?"))
+
+    def measure_current(self):
+        return float(self._query("MEAS:CURR?"))
+
+    def measure_power(self):
+        return float(self._query("MEAS:POW?"))
+
+    def disconnect(self):
+        self._inst.close()

tools/eload_manual_control.py

@@ -0,0 +1,114 @@
+import sys
+import time
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import msvcrt
+
+from drivers.eload import Eload, EloadError
+
+
+def main():
+    com_input = input("Enter COM port number (e.g., 5 for COM5): ").strip()
+    try:
+        com_num = int(com_input)
+    except ValueError:
+        print("Invalid input. Please enter a numeric COM port number.")
+        return
+
+    resource_name = f"ASRL{com_num}::INSTR"
+    try:
+        eload = Eload(resource_name)
+    except EloadError as exc:
+        print(f"Failed to open port {resource_name}: {exc}")
+        return
+
+    eload.set_remote()
+    quick_voltage_mode = False
+
+    while True:
+        cmd = input("\nCommand [on/off/set | manual/remote | status/monitor | setopt | exit]: ").strip().lower()
+
+        try:
+            if cmd == "set":
+                eload.set_mode_cv()
+                v = float(input("Enter voltage setpoint (V): ").strip())
+                eload.set_voltage(v)
+                print(f"Set voltage to {v} V.")
+
+                if not quick_voltage_mode:
+                    i_pos = float(input("Enter positive current limit I+ (A): ").strip())
+                    i_neg = float(input("Enter negative current limit I- (A): ").strip())
+                    eload.set_current_limit_positive(i_pos)
+                    eload.set_current_limit_negative(i_neg)
+                    print(f"Set I+ limit = {i_pos} A, I- limit = {i_neg} A.")
+
+                time.sleep(1)
+                print(f"Measured voltage after set: {eload.measure_voltage()} V")
+                print(f"Measured current after set: {eload.measure_current()} A")
+
+            elif cmd == "setopt":
+                quick_voltage_mode = not quick_voltage_mode
+                mode_desc = "Voltage-only SET enabled" if quick_voltage_mode else "Full voltage+current SET enabled"
+                print(f"Set behavior changed: {mode_desc}.")
+
+            elif cmd == "on":
+                eload.output_on()
+                time.sleep(1)
+                if eload.is_output_on():
+                    print("Output is ON.")
+                    print(f"Measured voltage: {eload.measure_voltage()} V")
+                    print(f"Measured current: {eload.measure_current()} A")
+                else:
+                    print("Failed to turn ON.")
+
+            elif cmd == "off":
+                eload.output_off()
+                time.sleep(1)
+                v = eload.measure_voltage()
+                print(f"Measured voltage after OFF: {v} V")
+                print("Voltage properly dropped to ~0 V." if v <= 0.1 else "Warning: Voltage still present!")
+
+            elif cmd == "status":
+                print(f"Output status: {'ON' if eload.is_output_on() else 'OFF'}")
+                print(f"Measured voltage: {eload.measure_voltage()} V")
+                print(f"Measured current: {eload.measure_current()} A")
+
+            elif cmd == "monitor":
+                print("Monitor mode started. Press any key to stop.")
+                try:
+                    while True:
+                        print(f"Voltage: {eload.measure_voltage()} V | Current: {eload.measure_current()} A")
+                        for _ in range(10):
+                            if msvcrt.kbhit():
+                                msvcrt.getch()
+                                raise KeyboardInterrupt
+                            time.sleep(0.1)
+                except KeyboardInterrupt:
+                    print("\nMonitor mode stopped.")
+
+            elif cmd == "manual":
+                eload.set_local()
+                print("Switched to manual (local) mode.")
+
+            elif cmd == "remote":
+                eload.set_remote()
+                print("Switched back to remote control mode.")
+
+            elif cmd == "exit":
+                eload.set_local()
+                print("Exiting and returning to manual mode...")
+                break
+
+            else:
+                print("Unknown command. Please enter one of: on/off/set | manual/remote | status/monitor | setopt | exit.")
+
+        except EloadError as exc:
+            print(f"Eload error: {exc}")
+
+    eload.disconnect()
+
+
+if __name__ == "__main__":
+    main()