Python wrapper for the ThingMagic Mercury API

The ThingMagic Mercury API is used to discover, provision and control ThingMagic RFID readers.

Reading RFID tags is as simple as this:

import mercury
reader = mercury.Reader("tmr:///dev/ttyUSB0")

reader.set_region("EU3")
reader.set_read_plan([1], "GEN2")
print(reader.read())

Installation

On Windows, use the pre-compiled binary installer.

On Linux:

• Check prerequisites using apt-get install unzip patch xsltproc gcc libreadline-dev,
• Then build and install using pip install python-mercuryapi.

Note: The build process will (temporarily) require upto 500MB of free space in /tmp. If your /tmp is smaller, use e.g. pip install python-mercuryapi -b $HOME/tmp to redirect.

Alternatively, you can follow the Build Instructions below and install the software manually.

Usage

Import the module mercury and create an mercury.Reader object.

import mercury

Reader Object

Represents a connection to the reader.

mercury.Reader(uri, baudrate=115200, antenna, protocol)

Object constructor. Connects to the reader:

• uri identifies the device communication channel:
  • "tmr:///com2" is a typical format to connect to a serial based module on Windows COM2
  • "tmr:///dev/ttyUSB0" is a typical format to connect to a USB device named ttyUSB0 on a Unix system
  • "llrp://192.198.1.100" is a typical format to connect to an Ethernet device (works on Linux only)
• baudrate defines the desired communication speed of the serial port. Supported values include 110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600 and 115200 (default). This parameter is not allowed for network-connected readers.
• antenna number and protocol for operations not using the read-plan (see bellow)

For example:

reader = mercury.Reader("tmr:///dev/ttyUSB0", baudrate=9600)

or

reader = mercury.Reader("tmr://192.168.1.101")

reader.set_read_plan(antennas, protocol, epc_target=None, bank=[], read_power=default)

Specifies the antennas and protocol to use for a search:

• antennas list define which antennas (or virtual antenna numbers) to use in the search
• protocol defines the protocol to search on. Supported values are:
  • "GEN2", UPC GEN2
  • "ISO180006B", ISO 180006B
  • "UCODE", ISO 180006B UCODE
  • "IPX64", IPX (64kbps link rate)
  • "IPX256", IPX (256kbps link rate)
  • "ATA"
• epc_target defines tags to be addressed (see Filtering)
• bank defines the memory banks to read. Supported values are:
  • "reserved"
  • "epc"
  • "tid"
  • "user"
• read_power defines the transmit power, in centidBm, for read operations. If not given, a reader specific default value is used.

For example:

reader.set_read_plan([1], "GEN2")

or

reader.set_read_plan([1], "GEN2", bank=["user"], read_power=1900)

Target filtering

The epc_target may be:

• None to address all tags
• Single hexa-string, e.g. b'E2002047381502180820C296' to address a tag with specific data (non-protocol-specific)
• List of hexa-strings to address multiple Gen2 tags with given EPC
• List of Gen2 Select filters (or even a single Gen2 filter) to address a given tag population (see below).

The Gen2 Select filter is a Dict with arguments:

• reserved, epc, tid, or user that defines the mask as a hexa-string. This also determines the memory bank in which to compare the mask.
• invert flag to match tags not matching the mask (by default false)
• bit indicating the location (in bits) at which to begin comparing the mask (by default 32 for the epc bank and 0 otherwise)
• len indicating length (in bits) of the mask (by default, the entire hexa-string given will be matched)
• action defines the filter action on the matching and not-matching tags (by default, on&off for the first filter in the list and on&nop otherwise)

The tuples are processed sequentially and depending on the action the selection (SL) of matching and not-matching tags is either asserted, deasserted or negated. The read/write operation is applied to the tags that remain asserted after processing the entire filter.

To select one tag or another, use on&off, followed by a sequence of on&nop. For example:

[b'E2002047381502180820C296', b'0000000000000000C0002403']

is equivalent to

[{'epc':b'E2002047381502180820C296', 'action':'on&off'}, {'epc':b'0000000000000000C0002403', 'action':'on&nop'}]

Please note that the assertion is a state of the (physical) tag that disappears after some time. Therefore, the result of one operation may affect another!

reader.read(timeout=500)

Performs a synchronous read, and then returns a list of TagReadData objects resulting from the search. If no tags were found then the list will be empty.

• timeout sets the reading time

For example:

print(reader.read())
[EPC(b'E2002047381502180820C296'), EPC(b'0000000000000000C0002403')]

To get a list (or a set) of EPC codes you can use the map function:

epcs = map(lambda t: t.epc, reader.read())
print(list(epcs))
[b'E2002047381502180820C296', b'0000000000000000C0002403']
print(set(epcs))
{b'E2002047381502180820C296', b'0000000000000000C0002403'}

reader.write(epc_code, epc_target=None)

Performs a synchronous write. Returns True upon success, or False if no tag was found. Upon failure an exception is raised.

For example:

old_epc = b'E2002047381502180820C296'
new_epc = b'E20020470000000000000012'

reader = Reader('llrp://192.168.0.2')
reader.set_read_plan([1], "GEN2")

if reader.write(epc_code=new_epc, epc_target=old_epc):
    print('Rewrited "{}" with "{}"'.format(old_epc, new_epc))
else:
    print('No tag found')

reader.enable_stats(callback)

Provide reader stats during asynchronous tag reads.

The function must be called before reader.start_reading().

For example:

def stats_received(stats):
    print({"temp" : stats.temperature})
    print({"antenna" : stats.antenna})
    print({"protocol" : stats.protocol})
    print({"frequency" : stats.frequency})

reader.enable_stats(stats_received)

reader.start_reading(callback, on_time=250, off_time=0)

Starts asynchronous reading. It returns immediately and begins a sequence of reads or a continuous read. The results are passed to the callback. The reads are repeated until the reader.stop_reading() method is called

• callback(TagReadData) will be invoked for every tag detected
• on_time sets the duration, in milliseconds, for the reader to be actively querying
• off_time duration, in milliseconds, for the reader to be quiet while querying

For example:

reader.start_reading(lambda tag: print(tag.epc))
b'E2002047381502180820C296'
b'0000000000000000C0002403'

reader.stop_reading()

Stops the asynchronous reading started by reader.start_reading().

For example:

reader.stop_reading()

reader.read_tag_mem(bank, address, count, epc_target=None)

Reads bytes from the memory bank of a tag. Returns a bytearray or None if no tag was found. Upon failure an exception is raised.

The read-plan is not used. Use the antenna and protocol parameters in the Reader constuctor.

For example:

reader = mercury.Reader("tmr:///dev/ttyUSB0", baudrate=9600, protocol="GEN2")
print(reader.read_tag_mem(1, 0x08, 8))
bytearray(b'\x00\x00\x00\x16\x12\x00\x00\x61')

reader.write_tag_mem(bank, address, data, epc_target=None)

Writes bytes to the memory bank of a tag. Returns True upon success, or False if no tag was found. Upon failure an exception is raised.

The read-plan is not used. Use the antenna and protocol parameters in the Reader constuctor.

For example:

reader.write_tag_mem(1, 0x08, bytearray(b'\x00\x00\x00\x16\x12\x00\x00\x61'))

reader.gpi_get(pin)

Returns value of a GPIO pin, or None is the pin is not configured as input (see get_gpio_inputs).

For example:

print(reader.get_gpio_inputs())
[1]
print(reader.gpi_get(1))
True

reader.gpo_set(pin, value)

Sets value of a GPIO pin configured as output (see get_gpio_outputs).

For example:

print(reader.get_gpio_outputs())
[1]
reader.gpo_set(1, False)

reader.get_model()

Returns a model identifier for the connected reader hardware.

For example:

print(reader.get_model())
M6e Nano

reader.get_software_version()

Returns the software version of the reader hardware For example:

print(reader.get_sofware_version())
01.0B.03.11-20.19.07.12-BL12.12.13.00

01.0B.03 is the current firmware version

reader.get_serial()

Returns a serial number of the reader, the same number printed on the barcode label.

reader.set_region(region)

Controls the Region of Operation for the connected device:

• region represents the regulatory region that the device will operate in. Supported values are:
  • "NA", North America/FCC
  • "NA2"
  • "NA3"
  • "EU", European Union/ETSI EN 302 208
  • "EU2", European Union/ETSI EN 300 220
  • "EU3", European Union/ETSI Revised EN 302 208
  • "IS", Israel
  • "IN", India
  • "JP", Japan
  • "KR", Korea MIC
  • "KR2", Korea KCC
  • "PRC", China
  • "PRC2"
  • "AU", Australia/AIDA LIPD Variation 2011
  • "NZ", New Zealand

For example:

reader.set_region("EU3")

reader.get_supported_regions()

Lists supported regions for the connected device.

For example:

print(reader.get_supported_regions())
['NA2', 'IN', 'JP', 'PRC', 'EU3', 'KR2', 'AU', 'NZ']

reader.get_hop_table()

Gets the frequencies for the reader to use, in kHz.

reader.set_hop_table(list)

Sets the frequencies for the reader to use, in kHz.

reader.get_hop_time()

Gets the frequency hop time, in milliseconds.

reader.set_hop_time(num)

Sets the frequency hop time, in milliseconds.

reader.get_antennas()

Lists available antennas.

For example:

print(reader.get_antennas())
[1, 2]

reader.get_connected_ports()

Returns numbers of the antenna ports where the reader has detected antennas.

For example:

print(reader.get_connected_ports())
[1]

reader.get_power_range()

Lists supported radio power range, in centidBm.

For example:

print(reader.get_power_range())
(0, 3000)

reader.get_read_powers()

Lists configured read powers for each antenna. [(antenna, power)]. The list does not include antennas with default power setting, so the list may be empty.

For example:

print(reader.get_read_powers())
[(1, 1800), (2, 3000)]

reader.get_write_powers()

Lists configured write powers for each antenna. [(antenna, power)].

reader.set_read_powers(powers)

Set the read power for each listed antenna and return the real setted values. Setted values may differ from those passed due to reader rounding.

• powers list of 2-tuples that include:
  • which antenna (or virtual antenna numbers) is going to be setted
  • required power, in centidBm, for the antenna, overriding the value from set_read_plan or reader specific default. The value must be within the allowed power range.

For example:

setted_powers = reader.set_read_powers([(1, 1533), (2, 1912)])
print(setted_powers)
[(1, 1525), (2, 1900)]

reader.set_write_powers(powers)

Set the write power for each listed antenna and return the real setted values.

reader.get_gpio_inputs()

Get numbers of the GPIO pins available as input pins on the device.

For example:

print(reader.get_gpio_inputs())
[1, 2]

reader.set_gpio_inputs(list)

Set numbers of the GPIO pins available as input pins on the device.

For example:

reader.set_gpio_inputs([1, 2])

reader.get_gpio_outputs()

Get numbers of the GPIO pins available as output pins on the device.

reader.set_gpio_outputs(list)

Set numbers of the GPIO pins available as output pins on the device.

On some devices this parameter is not writeable. Thus, instead of calling set_gpio_outputs with the a set you may need to call set_gpio_inputs with the pin omitted.

reader.get_gen2_blf()

Returns the current Gen2 BLF setting.

For example:

print(reader.get_gen2_blf())
250

reader.set_gen2_blf(blf)

Sets the Gen2 BLF. Supported values include:

• 250 (250KHz)
• 320 (320KHz)
• 640 (640KHz)

Not all values may be supported by a particular reader. If successful the input value will be returned. For example:

print(reader.set_gen2_blf(640))
640

reader.get_gen2_tari()

Returns the current Gen2 Tari setting.

For example:

print(reader.get_gen2_tari())
0

reader.set_gen2_tari(tari)

Sets the Gen2 Tari. Supported values include:

• 0 (25 us)
• 1 (12.5 us)
• 2 (6.25 us)

If successful the input value will be returned. For example:

print(reader.set_gen2_tari(1))
1

reader.get_gen2_tagencoding()

Returns the current Gen2 TagEncoding setting.

For example:

print(reader.get_gen2_tagencoding())
0

reader.set_gen2_tagencoding(tagencoding)

Sets the Gen2 TagEncoding. Supported values include:

• 0 (FM0)
• 1 (M = 2)
• 2 (M = 4)
• 3 (M = 8)

If successful the input value will be returned. For example:

print(reader.set_gen2_tagencoding(2))
2

reader.get_gen2_session()

Returns the current Gen2 Session setting.

For example:

print(reader.get_gen2_session())
0

reader.set_gen2_session(session)

Sets the Gen2 Session. Supported values include:

• 0 (S0)
• 1 (S1)
• 2 (S2)
• 3 (S3)

If successful the input value will be returned. For example:

print(reader.set_gen2_session(2))
2

reader.get_gen2_target()

Returns the current Gen2 Target setting.

For example:

print(reader.get_gen2_target())
0

reader.set_gen2_target(target)

Sets the Gen2 Target. Supported values include:

• 0 (A)
• 1 (B)
• 2 (AB)
• 3 (BA)

If successful the input value will be returned. For example:

print(reader.set_gen2_target(2))
2

reader.get_gen2_q()

Returns the current Gen2 Q setting as a tuple containing the current Q type, and initial Q value.

For example:

print(reader.get_gen2_q())
(0, 16)

reader.set_gen2_q(qtype, initialq)

Sets the Gen2 Q.

• qtype defines Dynamic vs Static Q value where:
  • 0 (Dynamic)
  • 1 (Static)
• initialq defines 2^initialq time slots to be used initially for tag communication.

If Dynamic Q is used then the input initialq value is ignored as the reader will choose this on its own. It is then likely for initialq on a get to be different than the value used on a set.

If successful the input value will be returned. For example:

print(reader.set_gen2_q(0, 4))
(0, 4)
print(reader.get_gen2_q())
(0, 64)

or

print(reader.set_gen2_q(1, 4))
(1, 4)
print(reader.get_gen2_q())
(1, 4)

reader.get_temperature()

Returns the chip temperature in degrees of Celsius.

TagReadData Object

Represents a read of an RFID tag:

• epc corresponds to the Electronic Product Code
• phase of the tag response
• antenna indicates where the tag was read
• read_count indicates how many times was the tag read during interrogation
• rssi is the strength of the signal recieved from the tag
• frequency the tag was read with
• timestamp of the read, in floating-point seconds for datetime.fromtimestamp
• epc_mem_data contains the EPC bank data bytes
• tid_mem_data contains the TID bank data bytes
• user_mem_data contains the User bank data bytes
• reserved_mem_data contains the Reserved bank data bytes

print(tag.epc)
b'E2000087071401930700D206'
print(tag.antenna)
2
print(tag.read_count)
2
print(tag.rssi)
-65
print(datetime.fromtimestamp(tag.timestamp))
2018-07-29 09:17:13.812189
print(tag.user_mem_data)
bytearray(b'\x00\x00\x00...')

Please note that the bank data bytes need to be requested via the bank parameter of the reader.set_read_plan function. Data not requested will not be read.

The friendly string representation (str) of the tag data is its EPC.

print(tag)
b'E2000087071401930700D206'

However, to avoid ambiguity, the string representation (repr) includes a prefix.

print(repr(tag))
EPC(b'E2000087071401930700D206')

Build Instructions

Windows

Use the Windows installer for the latest release and Python 3.6.

If you get the "ImportError: DLL load failed", make sure you have the Microsoft Visual C++ 2010 Redistributable Package installed.

To build an installer for other Python releases you need to:

• Download the latest Mercury API, e.g. mercuryapi-1.31.1.36-2.zip.
• Go to mercuryapi-1.31.2.40\c\src\api\ltkc_win32 and run gencode.bat
• Open mercuryapi-1.31.2.40\c\src\api\ltkc_win32\inc\stdint_win32.h and comment (or delete) the block of typedef for int_fast8_t through uint_fast64_t (8 lines)
• Download the latest pthreads-win32 binaries (both .dll and .lib) for your architecture and put them into mercuryapi-1.31.2.40\c\src\pthreads-win32\x86 or \x64
• Obtain Microsoft Visual Studio 2017, including the Python extensions
• Open the Solution and review the setup-win.py
  • Verify the mercuryapi directory
  • Set library_dirs and data_files to the pthreads-win32 you downloaded
  • Set Script Arguments to bdist_wininst -p win32 (default) or bdist_wininst -p amd64
• Start setup-win.py (without debugging)

Linux

First, make sure you have the required packages

yum install unzip patch libxslt gcc readline-devel python-devel python-setuptools

or

apt-get install unzip patch xsltproc gcc libreadline-dev python-dev python-setuptools

Both Python 2.x and Python 3.x are supported. To use the Python 3.x you may need to install the python3-dev[evel] instead of the python-dev[evel] packages.

Build the module simply by running

git clone https://github.com/gotthardp/python-mercuryapi.git
cd python-mercuryapi
make

This will download and build the Mercury API SDK and then it will build the Python module itself.

The make command will automatically determine which Python version is installed. If both 2.x and 3.x are installed, the 3.x takes precedence. To build and install 2.x you need to explicitly specify the Python interpreter to use:

sudo make PYTHON=python

Then, install the module by running

sudo make install

which is a shortcut to running

sudo python setup.py build install

If you are getting a "Module not found" error, please double check that you built and installed the module using the same Python version (2 or 3) you now use to run your script. (Or simply build and install it twice: once with python2 and once with python3.)

To access ports like /dev/ttyUSB0 as a non-root user you may need to add this user to the dialout group:

sudo usermod -a -G dialout $USER

MacOS X (Darwin)

To build on Mac

• Copy mercuryapi_osx.patch to mercuryapi.patch (and overwrite the target)
• Run make

Or simply do python setup.py build install

Copyright and Licensing

The python-mercuryapi is distributed under the terms of the MIT License. See the LICENSE.

Copyright (c) 2016-2019 Petr Gotthard