Fisher & Paykel MR720 Humidifier User Manual


 
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Ref. 185040646 MR730/720/700/480 Technical Manual ¯ Revision F ¯ Issued March 2001
Errors EP2 to EP4 can be caused for example by abnormal high differential temperatures on the two thermistors or by
rapidly changing input temperatures.
EP1 Hardware fault; Q13 short not effective.
EP2 Low probe temperature (~0 °C).
EP3 High probe temperature (~70 °C).
EP4 Partial short between the active probe cable conductors.
A5 MR700 SERIES HUMIDIFIER SERIAL DATA INTERFACE
A5.1 SERIAL DATA FORMAT
1 byte : (semi colon) Marks beginning of data record.
4 bytes ASCII Temperature Control setting.
4 bytes ASCII Airway temperature.
4 bytes ASCII Chamber temperature.
4 bytes ASCII Heaterplate temperature.
4 bytes ASCII Heater wire duty cycle.
4 bytes ASCII Heaterplate duty cycle.
4 bytes ASCII Chamber Control setting .
4 bytes * Status information. (1*ASCII 3*binary bytes).
2 bytes CR, LF (Marks end of data record).
Between each of the above lines there is approximately a 50 ms pause before the next line is transmitted. The complete
data record is repeated every 500 to 600 ms (500 ms on a 60 Hz supply, 600 ms with 50 Hz).
Data format is RS232 levels, no handshaking, 9600 baud, 8 bits, no parity, with one stop bit.
Between the semi colon and the line feed there are eight, 4-byte packets of information as shown above.
In each case the first byte of the packet contains an identification letter from ‘a’ through ‘h’ in ASCII.
The format of the 3 bytes following the ASCII I.D. is as shown below.
I.D. a - SET temperature.
I.D. b - Airway temperature.
I.D. c - Chamber temperature.
Range 5.0 to 80.0 °C, decimal point is assumed between 1st and 2nd digits.
I.D. d - Heaterplate temperature.
Range 14.0 to 99.9 °C decimal point assumed, 100 to 135°C no decimal point.
I.D. e - Heater Wire duty cycle.
I.D. f - Heaterplate duty cycle.
Range 0 to 100 %.
I.D. g - Chamber Control Setting.
Range -5.0 to +2.0 decimal point assumed. Plus or minus sign in leading ASCII byte.
I.D. h - Status information.
A5.2 STATUS INFORMATION
The ASCII I.D. is followed by three binary bytes giving alarms and error information, see list below: