The IMS is an FPGA-based device designed to continuously count the number of TTL (3.3 V) digital pulses in one of three available time intervals (1s, 1ms, 1μs). The IMS is capable of counting just over 50 million pulses per second. The device was built specifically to work with a Single Photon Counting Module based on an avalanche photodiode, but it can also be used as a frequency meter of some periodic signals. Once turned on, the device continuously measures the number of pulses per second and updates the measurement displayed on the HDMI monitor screen accordingly. This measurement is also made available to the user via Ethernet (UDP). The user can switch the device to a different time measurement range than one second (1s). Ranges of one millisecond (1ms) and one microsecond (1us) are also available. In addition to the main measurement of the number of pulses per chosen time period, the device additionally displays on the HDMI screen the global number of pulses counted since the device was turned on and the length of the last measured pulse in nanoseconds (with a precision of 4 ns). There is no need to configure the IMS IP address. The IMS uses Broadcast UDP Communication. It is possible to connect the IMS directly to the Ethernet port of your PC. In this case, however, you must manually configure an IP address and a network mask on your computer.