Fisher & Paykel MR480, MR720, MR730, MR700 technical manual Error Messages, A2.3 Integral Display

44

A2.2 ENGINEERING FUNCTIONS: NON HEATER WIRE MODE

SET	Set temperature display (°C)
dc	Heaterplate duty cycle (%)
hP	Heaterplate temperature (°C)
L	Programming link status
CP	Compare probes (Probe test)
i	Heaterplate Integral

A2.3 INTEGRAL DISPLAY

The integral is an error offset signal which constantly accrues to compensate for the temperature difference between the set control and probe. It is displayed in the ‘Ei’ and ‘Ti’ engineering functions in hexadecimal notation, ie. the count progresses from 0 to 9 then continues through A b c d E F before cycling back to 0. A negative integral is indicated by the three ‘decimal points’ in the display being lit. The magnitude of the integral is ± EFF (± 3839 in decimal notation).

A3 PROGRAMMING CONTROL OPTIONS

The following options can be enabled by joining the pads on the control PCB as shown.

x = don’t care. 1 = link.

0 = no link.

L1	L2	L3
x	x	0	ISO draft standard audio alarm.
x	x	1	Gliding tone audio alarm.
1	0	x	50 °C maximum temperature Heaterplate.
1	1	x	80 °C maximum temperature Heaterplate.
0	1	x	90 °C maximum temperature Heaterplate.
0	0	x	110 °C maximum temperature Heaterplate.

The state of the above links can be displayed in the engineering menu (‘L’).

The factory default settings are for the ISO alarm and 110 °C heaterplate, except MR720 which has an 80 °C heaterplate.

A4 ERROR CODES

During operation, if the microprocessor U3 does not receive an expected interrupt within a given time window an error condition will be flagged. In particular the RST6.5 interrupt which marks the termination of the integration ramp from U10-E and also controls the counter in U4 will, in the event of the count exceeding certain limits, generate an error message.

Some of the error indications which can be displayed on the MR700 Series digital display are listed below, with an explanation of the possible cause.

Error Messages

Ec	Checksum error (possible failure of U1 EPROM).
En	Memory test error (possible failure of U4 RAM).
EXx	Where X = 0 through 7, indicating multiplexer stage where error occurred.
	Where x = o or u, indicating ADC overflow error or underflow error, at the indicated multiplexer stage. (ADC
	counts outside the expected range will generate either an under or overflow error).
b-1	The Mute button is on at turn on or has been on for > 5 minutes.
b-2	The Standby button is on (see b-1 above).
F-2	The Heater Wire fuse, F2 is open circuited.

---Temperature sensor probe fault (see Sect.3.1).

The following errors may occur during the software-driven shorted probe cable test. If the errors do not persist they do not necessarily indicate a faulty probe assembly. It is because of conflicting results during the test that a definite conclusion cannot immediately be made.

Ref. 185040646 MR730/720/700/480 Technical Manual ¯ Revision F ¯ Issued March 2001