controllers: print+exit instead of raising exception for argparse error, better doc for --simulation

As long as you use --simulation, the driver will be in simulation mode.
Even if you specify a --device or --channels.

That can allow you to just switch to simulation mode by adding
--simulation in the device database without having to
remove the serial number or device path/name.

artiq/frontend/novatech409b_controller.py

@@ -4,6 +4,7 @@
 
 import argparse
 import logging
+import sys
 
 from artiq.devices.novatech409b.driver import Novatech409B
 from artiq.protocols.pc_rpc import simple_server_loop
@@ -22,7 +23,7 @@ def get_argparser():
         help="serial port.")
     parser.add_argument(
         "--simulation", action="store_true",
-        help="Put the driver in simulation mode.")
+        help="Put the driver in simulation mode, even if --device is used.")
     verbosity_args(parser)
     return parser
 
@@ -32,9 +33,9 @@ def main():
     init_logger(args)
 
     if not args.simulation and args.device is None:
-        raise ValueError("You need to specify either --simulation or "
-                         "-d/--device argument. Use --help for more "
-                         "information.")
+        print("You need to specify either --simulation or -d/--device "
+              "argument. Use --help for more information.")
+        sys.exit(1)
 
     dev = Novatech409B(args.device if not args.simulation else None)
     try:

artiq/frontend/pdq2_controller.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import argparse
+import sys
 
 from artiq.devices.pdq2.driver import Pdq2
 from artiq.protocols.pc_rpc import simple_server_loop
@@ -15,7 +16,7 @@ def get_argparser():
         help="serial port.")
     parser.add_argument(
         "--simulation", action="store_true",
-        help="Put the driver in simulation mode.")
+        help="Put the driver in simulation mode, even if --device is used.")
     parser.add_argument(
         "--dump", default="pdq2_dump.bin",
         help="file to dump pdq2 data into, for later simulation")
@@ -29,9 +30,9 @@ def main():
     port = None
 
     if not args.simulation and args.device is None:
-        raise ValueError("You need to specify either --simulation or "
-                         "-d/--device argument. Use --help for more "
-                         "information.")
+        print("You need to specify either --simulation or -d/--device "
+              "argument. Use --help for more information.")
+        sys.exit(1)
 
     if args.simulation:
         port = open(args.dump, "wb")

artiq/frontend/pxi6733_controller.py

@@ -2,6 +2,7 @@
 # Yann Sionneau <ys@m-labs.hk>, 2015
 
 import argparse
+import sys
 
 from artiq.protocols.pc_rpc import simple_server_loop
 from artiq.devices.pxi6733.driver import DAQmx, DAQmxSim
@@ -16,7 +17,8 @@ def get_argparser():
     parser.add_argument("-c", "--clock", default="PFI5",
                         help="Input clock pin name (default: PFI5)")
     parser.add_argument("--simulation", action='store_true',
-                        help="Put the driver in simulation mode.")
+                        help="Put the driver in simulation mode, even if "
+                             "--channels is used.")
     verbosity_args(parser)
     return parser
 
@@ -26,9 +28,9 @@ def main():
     init_logger(args)
 
     if not args.simulation and args.channels is None:
-        raise ValueError("You need to specify either --simulation or "
-                         "-C/--channels argument. Use --help for more "
-                         "information.")
+        print("You need to specify either --simulation or -C/--channels "
+              "argument. Use --help for more information.")
+        sys.exit(1)
 
     if args.simulation:
         daq = DAQmxSim()

artiq/frontend/thorlabs_tcube_controller.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 
 import argparse
+import sys
 
 from artiq.devices.thorlabs_tcube.driver import Tdc, Tpz, TdcSim, TpzSim
 from artiq.protocols.pc_rpc import simple_server_loop
@@ -16,7 +17,8 @@ def get_argparser():
                         help="serial device. See documentation for how to "
                              "specify a USB Serial Number.")
     parser.add_argument("--simulation", action="store_true",
-                        help="Put the driver in simulation mode.")
+                        help="Put the driver in simulation mode, even if "
+                             "--device is used.")
     simple_network_args(parser, 3255)
     verbosity_args(parser)
     return parser
@@ -27,9 +29,9 @@ def main():
     init_logger(args)
 
     if not args.simulation and args.device is None:
-        raise ValueError("You need to specify either --simulation or "
-                         "-d/--device argument. Use --help for more "
-                         "information.")
+        print("You need to specify either --simulation or -d/--device "
+              "argument. Use --help for more information.")
+        sys.exit(1)
 
     if args.simulation:
         if args.product == "TDC001":