K-Patents PR-01-S - Manual (Page 59)

INSTRUCTION MANUAL FOR K-PATENTS PR-01-S (-AX/FM/CS) DOCUMENT/REVISION No. INM 1/14
Effective: May 15, 2009
57
Raw data explanations:
RMN, RMX: Minimum and maximum of the raw video signal. This signal is calculated on
the Processor card from the video signal. The scale is 0 - 255, corresponding
to full scale on display.
LED: The LED current control signal on a scale 0-255 corresponding to 0 -8 mA.
This is the current control signal from the Processor, and not an actual
measurement of the LED current. The red light of the LED can be seen
directly. If the operation is correct, the displayed LED value should be above
20 and below 200.
Scans: Number of optical images during one calculation cycle, typically 3 to 4. The
scan pulses (with 5 V amplitude) can be measured at TP 3 (Figure 6.50).
A/D: This refers to the temperature measurement, Section 6.6.
Sts: Sensor status bits. Should be "00h" for a standard and Intrinsically Safe
sensor. Status "01h" indicates "Detector timeout".
HT: Sensor head temperature sensor reading. This value is used in calculating the
actual Sensor head internal temperature.
HH: Sensor head humidity sensor reading. The actual relative humidity in the
Sensor is calculated from HH and HT.
Sensor faults:
Sensor faults can be distinguished by the following indications:
The diagnostic message ** No sensor signals **:
The fault may be in the single path from Image digitizer to the interconnecting cable to the
Processor card, see Figure 6.22. If the signal path is OK, then the Image digitizer does not work.
Check the 24 V and the 5 V supply to Processor card, Figure 6.52. If the supply is OK, change the
Image digitizer card.
The diagnostic message ** Detector timeout **:
The scan pulses (Figure 6.50) are missing at TP 3 (Figure 6.52). Check the 15 V supply to the
Image detector card, Figure 6.52. If the 15 V supply is OK, but the sync signal TP2 is absent, then
change the Image detector card. The sync signal is similar to the video signal but the pulse
amplitude is constant. Check also the main power selection switch position, see Section 3.6.
A way to check the function of the Sensor is to place an opaque screen before the CCD-element, see the
arrow marked "screen" in Figure 6.50. When the screen blocks the light to the photocell, the video pulses
should decrease. When the Max value drops below 200, the LED control signal should increase, which in
turn should make the LED brighter.
If a light e.g. from a flashlight is directed on the screen to illuminate the photocells, then the video signal
should increase, the LED control should decrease and the LED should get dimmer.