uniphy Phyaction 740 Series, Информация о сервисе

Страница: 31 / 68

Service Information Phyaction 740 & 790-series Page 29
6.1 and 8.0 V (on ADC 1.10 and 1.45 V, ADC-values 00E1 and 0128h). When the voltage is out of
range
ERROR 60 is reported, with error value the measured ADC-value.
5 Optocoupler test. The voltage returned from the optocouplers for high resistance check (patient
circuit resistance) must be between 3.75 V and 4.25 V (ADC-values 02FFh and 0365h) in case
there is no output current set.
ERROR 42 will be generated in case this test fails, with error value
the measured ADC-value.
After this test the current generator is initialised:
-
the DACs are initialised,
- the choppers are set to 40 kHz,
- waveform table 3 (galvanic x sine) is selected,
- the MF frequency is set to 4 kHz.
SAFETY AND DUMMY RELAY TEST
In the following test sequence the safety and dummy relay's are tested for proper functioning. No external
(patient) connection should exist during this test. The DAC is programmed in such a way that with a test
reference voltage applied via the TEST line approximately 2 mA will flow through the output circuit, if
connected either through an external connection or the dummy relay. The voltage level at the tracing
series regulator is proportionate to the resistance in the output (patient) circuit with a given current. This
level is used to test the output circuit resistance. A voltage on this point below 10.9 V if checking for an
open circuit is recognized as an error. A voltage above 8.25 V while testing for a closed circuit is
recognized as error.
When the safety relay is energized (on) the contacts are closed. The dummy relay will short circuit the
output channel if in energized (on) state.
1
Test if the safety relay is off. A low current (apr. 2 mA) is applied to the output circuit. If a closed
circuit is detected (Vmf < 10.9 V, on ADC 1.97 V, ADC-value 0193h) ERROR 61 will occur, with error
value the measured ADC-value.
2 Test if errorline becomes activated if the safety relay is switched on. If the error line is activated
within 10 msec it means that the safety circuit has activated it and ERROR 55 will occur.
3 Test if the safety relay makes contact. With the safety relay on and the dummy relay on a closed
circuit should exist. An open circuit (Vmf > 8.25 V, on ADC 1.49 V, ADC-value 0130h) will result in
ERROR 62 , with error value the measured ADC-value.
4 Test for external (patient) connections. When the dummy relay is switched off the output circuit
should be open again. A closed circuit indicates an external connection. ERROR 63 is reported
when Vmf is below 10.9 V (1.97 V on ADC, ADC-value 0193h), with error value the measured ADC-
value.
5 Test if dummy relay makes contact. After energizing the dummy relay the outputs should be
shorted. If Vmf is above 8.25 V (1.49 V on ADC, ADC-value 0130h) ERROR 64 occurs, with error
value the measured ADC-value.
6 Dosage regulator at zero, checked by means of the potentiometer switch. If not at zero
ERROR 50 .
If these tests have passed the safety and dummy relay are functioning and no external connections exist.
In the next test the safety relay is tested under full load conditions. The DAC's are programmed for an
output current of 110% maximum operating current. At the moment the safety relay is closed the safety
circuit should become active immediately, because the dose regulator is in the zero position.
1
Test if the safety relay switches under full load. When the safety relay is switched on, the safety
limit check circuits should activate the errorline causing the safety relay to drop off. If the errorline