Preamplifiers

Devices

Device	Tested	Connection
Stanford Research Systems SR560	Untested	RS-232

Functions

The SR560 interface keeps requested settings in attributes of each SR_560 instance. Getters return None until a value has been set through that instance or loaded by preamplifier_reset(). Opening a connection does not reset the instrument. The interface does not read replies from the instrument, and it cannot confirm that a command was accepted or detect changes made from the front panel or another controller. Setters return None and update the cache after writing the command.

The serial connection uses 9600 baud, 8 data bits, no parity, two stop bits, and CRLF line endings. Set SPECIFIC.address in the active device configuration to 0, 1, 2, or 3, matching the SR560 DIP-switch address. Every command is preceded by UNLS and LISN <address>.

The first application startup copies device configuration files only when the user configuration directory is missing or empty. If the active directory already exists and lacks SR_560_config.ini, copy only that file from atomize/device_modules/config/ into the directory returned by atomize.main.local_config.load_config_device() and edit its serial port as needed; preserve the other active settings. The default port is ASRL/dev/ttyUSB0::INSTR for Linux; on Windows, use the appropriate VISA resource, such as ASRL3::INSTR for COM3.

import atomize.device_modules.SR_560 as sr560

preamp = sr560.SR_560()

Run the example in test mode with python atomize/script_examples/devices_tests/ask_SR_560.py test on Windows, or use python3 on Linux. Test mode uses the same cached getters and checks arguments without opening the serial connection. Invalid settings raise AssertionError in test mode and ValueError during a real run.

preamplifier_name()

preamplifier_name()    # -> str; device name

This function returns the configured device name.

---

preamplifier_gain(*gain)

preamplifier_gain()       # -> int or None; cached gain
preamplifier_gain(20)     # set gain to 20

This function sets or returns the cached voltage gain. Allowed values are 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000, 2000, 5000, 10000, 20000, and 50000.

---

preamplifier_gain_mode(*mode)

preamplifier_gain_mode()                       # -> str or None; cached gain mode
preamplifier_gain_mode('High Dynamic Reserve')  # set gain mode

This function sets or returns the cached gain mode. Allowed values are 'Low Noise', 'High Dynamic Reserve', and 'Calibration'.

---

preamplifier_input_source(*source)

preamplifier_input_source()       # -> str or None; cached input source
preamplifier_input_source('A-B')  # select A minus B

This function sets or returns the cached input source. Allowed values are 'A', 'A-B', and 'B'.

---

preamplifier_input_coupling(*coupling)

preamplifier_input_coupling()       # -> str or None; cached input coupling
preamplifier_input_coupling('AC')   # set AC coupling

This function sets or returns the cached input coupling. Allowed values are 'Ground', 'DC', and 'AC'. AC coupling always inserts the 0.03 Hz high-pass filter. When AC coupling is selected, the low-pass filter is limited to a 6 dB/oct slope.

---

preamplifier_invert(*invert)

preamplifier_invert()        # -> str or None; cached inversion state
preamplifier_invert('On')    # enable inversion

This function sets or returns the cached signal inversion state. Allowed values are 'Off' and 'On'.

---

preamplifier_filter_mode(*mode)

preamplifier_filter_mode()            # -> str or None; cached filter mode
preamplifier_filter_mode('Bandpass')  # set bandpass filtering

This function sets or returns the cached filter mode. Allowed values are 'Bypass', '6 dB Low Pass', '12 dB Low Pass', '6 dB High Pass', '12 dB High Pass', and 'Bandpass'.

---

preamplifier_high_pass_frequency(*frequency)

preamplifier_high_pass_frequency()            # -> str or None; cached frequency
preamplifier_high_pass_frequency('10 Hz')     # set high-pass frequency

This function sets or returns the cached high-pass cutoff frequency. Pass a string using Hz, kHz, or MHz. Allowed frequencies are '0.03 Hz', '0.1 Hz', '0.3 Hz', '1 Hz', '3 Hz', '10 Hz', '30 Hz', '100 Hz', '300 Hz', '1 kHz', '3 kHz', and '10 kHz'. The getter returns these canonical unit strings. The SR560's AC coupling setting always inserts the 0.03 Hz high-pass filter.

---

preamplifier_low_pass_frequency(*frequency)

preamplifier_low_pass_frequency()             # -> str or None; cached frequency
preamplifier_low_pass_frequency('1 MHz')      # set low-pass frequency

This function sets or returns the cached low-pass cutoff frequency. Pass a string using Hz, kHz, or MHz. Allowed frequencies are '0.03 Hz', '0.1 Hz', '0.3 Hz', '1 Hz', '3 Hz', '10 Hz', '30 Hz', '100 Hz', '300 Hz', '1 kHz', '3 kHz', '10 kHz', '30 kHz', '100 kHz', '300 kHz', and '1 MHz'. The getter returns these canonical unit strings. AC coupling limits the low-pass filter to a 6 dB/oct slope. The cached value is the last requested setting; it does not represent an effective response measured from the instrument.

---

preamplifier_vernier(*vernier)

preamplifier_vernier()        # -> str or None; cached vernier state
preamplifier_vernier('On')    # enable vernier control

This function sets or returns the cached vernier state. Allowed values are 'Off' and 'On'.

---

preamplifier_vernier_gain(*gain)

preamplifier_vernier_gain()     # -> int or None; cached vernier gain
preamplifier_vernier_gain(50)   # set vernier gain to 50 percent

This function sets or returns the cached vernier gain as a percentage of the selected calibrated gain. Allowed values are the integers from 0 through 100, inclusive. Enable vernier control separately with preamplifier_vernier('On'). The getter initially returns None and remains None after reset because the manual does not document a reset value for this setting.

---

preamplifier_blanking(*blanking)

preamplifier_blanking()        # -> str or None; cached blanking state
preamplifier_blanking('On')    # enable blanking

This function sets or returns the cached blanking state. Allowed values are 'Off' and 'On'. The getter initially returns None and remains None after reset because the driver has no documented reset value for this setting.

---

preamplifier_overload_reset()

preamplifier_overload_reset()    # initiate overload recovery

This function sends the overload reset command, which resets overload for half a second to speed recovery with long filter time constants. It preserves the cached settings and does not return a value.

---

preamplifier_reset()

preamplifier_reset()    # restore instrument defaults and cache documented values

This function sends *RST, clears the instance cache, and records the documented default settings: gain 20, gain mode 'High Dynamic Reserve', input source 'A', input coupling 'DC', inversion 'Off', filter mode 'Bypass', high-pass frequency '0.03 Hz', low-pass frequency '1 MHz', and vernier 'Off'. Vernier gain and blanking remain None because the driver does not define documented reset defaults for them. The function does not return a value.

---

preamplifier_command(command)

preamplifier_command('GAIN 6')    # send the raw command for gain 100

This function sends a nonempty raw command string to the SR560 and clears every cached setting because the command may change any of them. Use preamplifier_reset() to restore the documented defaults and update the cache after reset; sending *RST through this function clears the cache without recording those defaults. The function does not return a value.