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PDM-IR user manual v
3.0.3
Micro Photon Devices S.r.l. – Italy All Rights Reserved
25
4.5.2
TTL AUX OUT
The TTL AUX OUT offers the possibility to interface and sync the PDM-IR with other instruments; in fact, the
LVTTL output levels (0 ÷ 3.3 V) allows to communicate with standard CMOS electronics.
4.5.3
NIM AUX OUT
The auxiliary output NIM AUX OUT is the negative levels signal (from 0 to -800mV providing -16 mA current
in a DC grounded 50 Ohm termination). The low-level signal (-800 mV) is voltage protected and cannot
provide a lower voltage, in case of unterminated lines. Moreover, the use of unterminated transmission lines
corrupts the rising edge of the signal and, as a result, the signal becomes unusable.
4.6
PDM-IR LED Status
The PDM-IR has a LED lens on the rear panel for showing the current module status. Table 9 shows the LED
colors and their meanings. Unless the PDM-IR has detected a serious error that is signaled with a RED colored
LED, the standard condition for the LED status is OFF. For this reason, it is important to understand the LED
color sequence during the most common procedures with the PDM-IR, like changing module parameters.
These typical sequences are described in Table 10.
Table 9.
LED color meaning.
OFF LED
when the LED is OFF, there are 2 possibilities: the module is not powered-ON or the
module is correctly working and the SPAD is enabled.
BLINKING
ORANGE
a blinking orange LED indicates that the PDM-IR is powered-ON but the SPAD is not
polarized. This state is active for less than 10 seconds after powering-ON the module
or whenever the SPAD has been turned off using the SDK or the VisualPDM-IR
software.
ORANGE LED
when the LED shows a stable Orange color, the PDM-IR is updating the its internal
working parameters (SPAD ON/OFF status, free-running/gated working mode, gate
parameter, …). At the end of any update procedure, the LED will always change to
GREEN, if the update procedure completes successfully with the SPAD enabled, to
BLINKING ORANGE if the update procedure completes successfully with the SPAD
disabled or to RED LED if there is an error.
GREEN LED
this LED color is used when the SPAD is correctly polarized and ready to detect
photons. The green color is always active only for 5 seconds to report the success of
an update procedure; after that, the LED will change status to the OFF state in order
to avoid measurement errors due to an unwanted light source.
RED LED
when red color is active, the SPAD is disabled for safety precautions as an error
occurred. In order to understand what happened, use the SDK or the VisualPDM-IR
for reading the error type.